New Detrital Zircon U-Pb Insights on the Palaeogeographic Origin of The

Geological Magazine New detrital zircon U–Pb insights on the

www.cambridge.org/geo palaeogeographic origin of the central Sanandaj–Sirjan zone, Iran

1,2,3 1 4 4 Original Article Farzaneh Shakerardakani , Franz Neubauer , Xiaoming Liu , Yunpeng Dong , Behzad Monfaredi5 and Xian-Hua Li2,3,6 Cite this article: Shakerardakani F, Neubauer F, Liu X, Dong Y, Monfaredi B, and 1 – Department of Geography and Geology, Paris-Lodron-University of Salzburg, Hellbrunner Str. 34, A-5020 Salzburg, Li X-H. New detrital zircon U Pb insights on the 2 palaeogeographic origin of the central Austria; State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of 3 Sanandaj–Sirjan zone, Iran. Geological Sciences, Beijing 100029, China; Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing 4 Magazine https://doi.org/10.1017/ 100029, China; State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, S0016756821000728 Northern Taibai Str. 229, Xi’an 710069, China; 5Institute of Earth Sciences – NAWI Graz Geocenter, University of Graz, Universitätsplatz 2, Graz 8010, Austria and 6College of Earth and Planetary Sciences, University of Chinese Received: 10 February 2021 Academy of Sciences, Beijing 100049, China Revised: 20 June 2021 Accepted: 22 June 2021 Abstract Keywords: New detrital U–Pb zircon ages from the Sanandaj–Sirjan metamorphic zone in the Zagros oro- Iranian microcontinent; Sanandaj–Sirjan metamorphic zone; U–Pb geochronology; genic belt allow discussion of models of the late Neoproterozoic to early Palaeozoic plate tec- detrital zircon; North Gondwana; tonic evolution and position of the Iranian microcontinent within a global framework. A total of palaeobiogeography 194 valid age values from 362 zircon grains were obtained from three garnet-micaschist samples. The most abundant detrital zircon population included Ediacaran ages, with the main age Author for correspondence: peak at 0.60 Ga. Other significant age peaks are at c. 0.64–0.78 Ga, 0.80–0.91 Ga, 0.94–1.1 Ga, Farzaneh Shakerardakani, – – Email: [email protected] 1.8 2.0 Ga and 2.1 2.5 Ga. The various Palaeozoic zircon age peaks could be explained by sediment supply from sources within the Iranian microcontinent. However, Precambrian ages were found, implying a non-Iranian provenance or recycling of upper Ediacaran–Palaeozoic clastic rocks. Trace-element geochemical fingerprints show that most detrital zircons were sourced from continental magmatic settings. In this study, the late Grenvillian age population at c. 0.94–1.1 Ga is used to unravel the palaeogeographic origin of the Sanandaj–Sirjan metamorphic zone. This Grenvillian detrital age population relates to the ‘Gondwana superfan’ sediments, as found in many Gondwana-derived terranes within the European Variscides and Turkish terranes, but also to units further east, e.g. in the South China block. Biogeographic evidence proves that the Iranian microcontinent developed on the same North Gondwana margin extending from the South China block via Iran further to the west.

1. Introduction The Gondwana supercontinent is the result of large-scale amalgamation of continents and microcontinents located within East and West Gondwana. Amalgamation started at the end of the Neoproterozoic period, which led to the formation of the East African orogen (e.g. Stern, 1994; Collins & Pisarevsky, 2005; Stampfli et al. 2013; Meinhold et al. 2013) and consequently records the first stage in the development of the Transgondwanan Supermountain (Squire et al. 2006). From the northern margin of Gondwana, major terranes split off during Palaeozoic time (Şengör, 1990 and references therein), moved to the north and were accreted to the Eurasian margin during Triassic and Cenozoic times (e.g. Agard et al. 2011; Abbo et al. 2015; Hassanzadeh & Wernicke, 2016; Stephan et al. 2019). Understanding the exact origin of these Gondwana-derived terranes along the Gondwana margin has been a major geological challenge in the last decade (e.g. Stampfli et al. 2013; von Raumer et al. 2013; Stephan et al. 2019; Žák et al. 2021; Fig. 1). Although most of the Neoproterozoic palaeogeographic reconstructions place the Iranian © The Author(s), 2021. Published by Cambridge microcontinent along the Prototethyan margin of northern Gondwana, which is close to the University Press. This is an Open Access article, East African orogen (e.g. Hassanzadeh et al. 2008; Horton et al. 2008; Fergusson et al. distributed under the terms of the Creative 2016), some new age information and the tectonic setting of the Neoproterozoic rocks indicate Commons Attribution licence (http:// creativecommons.org/licenses/by/4.0/), which that the Iranian microcontinent was originally part of a series of peri-Gondwanan terranes, sim- permits unrestricted re-use, distribution and ilar to the Avalonian (640–540 Ma) and Cadomian (616–540 Ma) arc terranes (e.g. Murphy reproduction, provided the original article is et al. 2004; Moghadam et al. 2020b; Fig. 1). properly cited. The age and nature of the continental crust in Iran have been documented during previous research, including zircon U–Pb ages published over the last two decades that demonstrate the dominance of Pan-African continental crustal material in the Iranian microcontinent, recording widespread late Neoproterozoic subduction-related magmatism (e.g. Ramezani & Tucker, 2003; Hassanzadeh et al. 2008; Rahmati-Illkchi et al. 2011; Jamshidi Badr et al. 2013; Nutman et al.

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Fig. 1. (Colour online) (a) Present-day map showing Gondwana-derived units (GDUs) and further terranes within the Alpine–Himalaya collision orogen (modified from Stampfli et al. 2013). GDUs and further terranes mentioned: AL– Alborz; ZG – Zagros; CI – Central Iran; KD – Kopet Dagh; AS – Arabian Shield; NS – Nubian Shield; SSMZ – Sanandaj–Sirjan metamorphic zone; Tu – Turan; Ba – Badakshan; SKu – South Kunlun; NQi – North Qilian; Qi – Qilian; Qa – Qaidam; EKu – East Kunlun; Er – Erlangping; Qin – Qinling; Da – Dabie. Light yellow – post-460 Ma formations; dark green – Hunia terrane (H); light blue – Gondwana.

2014; Shakerardakani et al. 2015; Fergusson et al. 2016; Moghadam (2020) suggested sediment supply from the Permian–Triassic mag- et al. 2018, 2020b). Recent research on amphibolites in the central matic rocks of the Silk Road Arc further north. The Neoproterozoic Sanandaj–Sirjan metamorphic zone (SSMZ) identified and Palaeoproterozoic zircons have predominantly rounded Neoarchaean xenocrystic zircons that revealed the presence of hid- shapes suggesting recycling of older sedimentary rocks den Neoarchaean crustal components in Iran (Shakerardakani (Meinhold et al. 2020). In NE Iran, the Ordovician to Lower et al. 2019). Devonian sandstones are characterized by distinct age groups at In addition, detrital zircon data from Neoproterozoic, 2.5 Ga, 0.6–0.8 Ga, 0.5 Ga and 0.4–0.5 Ga, as well as a minor age Palaeozoic and Triassic clastic sediments have recently become peak at 1.0 Ga (Moghadam et al. 2017). available from many different portions of the Iranian microconti- In this paper, we carry out, for the first time, a coupled U–Pb age nent, such as from the central Alborz, Zagros, northwestern and trace-element analysis of detrital zircons from three garnet- Central Iranian terrane and NE Iran (e.g. Horton et al. 2008; micaschist samples (primarily Neoproterozoic–early Palaeozoic Etemad-Saeed et al. 2015; Honarmand et al. 2016; Zhang et al. in age) distributed along a ~100 km long central segment of the 2017; Moghadam et al. 2017; Meinhold et al. 2020; Zoleikhaei SSMZ in the Zagros orogenic belt (Fig. 1). For the interpretation et al. 2020). of our results, we integrate our new data with the previously pub- Previous detrital zircon studies indicated that the dominant age lished detrital zircon U–Pb data from other Precambrian– population in the upper Neoproterozoic–Cambrian sandstones Palaeozoic clastic sediments throughout the Alborz, Central Iran from the Kahar, Bayandor, Barut, Lalun and Mila formations of and NE Iran. We juxtapose the new detrital U–Pb zircon data with the Alborz and Zagros mountains is Neoproterozoic, with a main biogeographic evidence to constrain the position of the Iranian age peak at 0.6 Ga as well as minor peaks at 1.0 Ga, 1.8 Ga and microcontinent on the northern Gondwana margin and its relation 2.5 Ga (Horton et al. 2008). In the central Alborz Mountains, to the global framework as was recently also postulated by Yang alongside the youngest, prominent (0.55–0.56 Ga) detrital zircon et al.(2020) and Merdith et al.(2021). We show that the SSMZ population, 0.9–1.0 Ga, 2.0–2.2 Ga, 2.5–2.7 Ga and 2.9–3.2 Ga as part of the Iranian microcontinent bears similar detrital zircon age populations appear in the Neoproterozoic sandstones from age spectra to those known from the Arabian–Nubian shield, in the Kahar Formation (Etemad-Saeed et al. 2015). In addition, peri-Gondwanan terranes to the west of Iran as well as to those Cambrian sandstones of the Lalun Formation reveal similar reoc- of the South China block in the east. curring age clusters as observed in the Kahar Formation, dominated by Cryogenian–Ediacaran ages, with pre-Neoproterozoic 2. Geological background and Cambrian zircon grains a minor component (Zoleikhaei et al. 2020). Some Neoproterozoic sandstones from the Kahar Iran is regarded as a fragment of Gondwana and comprises several and Bayandor formations in Central Iran are dominated by blocks or domains, e.g. the Alborz and Zagros mountain belts, the 0.62–0.64 Ga zircon ages, with minor age populations at Central Iranian plateau and the Kopet Dagh Mountains, that are 0.82 Ga, 0.92–0.94 Ga, 1.9–2.3 Ga and 2.5–3.0 Ga (Honarmand separated by deep-seated faults or suture zones (e.g. Stöcklin, et al. 2016). The dominant age population from Cambrian sand- 1968; Berberian & King, 1981; Fig. 1). Major areas of exposed crys- stones of the Zaigun Formation is Cryogenian to Tonian talline basement rocks with variable dimensions occur within all of (Grenvillian) (0.7–0.9 Ga), with subordinate Palaeoproterozoic the continental tectonic zones in Iran barring the Kopet Dagh to Neoarchaean (2.4–2.6 Ga) populations. However, the Triassic Mountains to the northeast. Nakhlak Group sandstones of Central Iran show a pronounced The NW–SE-trending Zagros orogen of western Iran is part of age population at c. 240–280 Ma, with subordinate pre-Permian the Alpine–Himalayan orogenic belt and developed as the result of Palaeozoic peaks at c. 320 Ma and 480 Ma. Meinhold et al. the continental collision between the African–Arabian continent

and the Iranian microcontinent (e.g. Berberian & King, 1981; that dip outward from the centre of the complex and juxtapose Alavi, 1994; Mohajjel et al. 2003; Agard et al. 2011; Mouthereau it against unmetamorphosed rocks in the hangingwall (Moosavi et al. 2012). The Zagros Mountains are subdivided into four par- et al. 2014; Shakerardakani et al. 2019, 2020). Besides rare rem- allel tectonostratigraphic zones, namely (from NE to SW) the nants of Neoarchaean rocks, the Muteh–Golpaygan metamorphic Urumieh–Dokhtar magmatic arc (UDMA), the SSMZ, the complex comprises mainly Neoproterozoic basement material Imbricate zone or High Zagros, and the Zagros fold–thrust belt dominated by granitic orthogneisses and metapelites locally inter- (Stöcklin, 1968; Falcon, 1974; Alavi, 1994; Fig. 2a). layered with marbles along with minor quartzite (e.g. Thiele, 1966; The SSMZ forms the innermost crystalline part of the Zagros Rachidnejad-Omran et al. 2002; Moritz et al. 2006; Moosavi et al. orogen, where the continental and oceanic units were tectonically 2014; Hassanzadeh & Wernicke, 2016). All these lithologies are juxtaposed against the Arabian plate along the Main Zagros thrust cross-cut by abundant leucogranitic rocks and dykes in the western (e.g. Agard et al. 2011; Hassanzadeh & Wernicke, 2016). The SSMZ part of the complex (Shakerardakani et al. 2020). The Neoarchaean is primarily composed of Precambrian–Palaeozoic metamorphic basement of the Muteh–Golpaygan metamorphic complex has and sedimentary sequences, which are unconformably overlain recently been constrained by 207Pb–206Pb ages of c. 2.7 and by Permian–Triassic marbles, Jurassic phyllites and Aptian– 2.5 Ga from xenocrystic zircons within amphibolite Albian limestones (Stöcklin, 1968; Berberian & King, 1981). In (Shakerardakani et al. 2019). Unmetamorphic to very low-grade addition, this zone represents the largest exposure and well-pre- metamorphic Mesozoic and Cenozoic shale, sandstone, siltstone, served record of key events during late Palaeozoic to middle slate, dolomite and conglomerate units overlie the basement rocks Cenozoic times, which represent the formation and destruction in the study area and are in turn mostly covered by of the Neotethys Ocean (e.g. Mohajjel et al. 2003; Hassanzadeh Quaternary rocks. & Wernicke, 2016). The SSMZ, Central Iran and (southern and The depositional age of the metapelitic rocks from the Muteh– central) Alborz are considered part of the Iranian microcontinent, Golpaygan metamorphic complex is unknown. The metapelites bearing a similar late Ediacaran–Palaeozoic and Mesozoic stratig- are dominantly characterized by amphibolite-facies mineral raphy (e.g. Hassanzadeh & Wernicke, 2016; Moghadam et al. 2017 assemblages, including garnet, staurolite and kyanite (Moritz and references therein). et al. 2006). K–Ar amphibole ages of c. 156 Ma (Rachidnejad- Omran et al. 2002) suggest that metamorphism was predominantly 3. Geological setting and sampling of Late Jurassic age (Moosavi et al. 2014; Hassanzadeh & Wernicke, 2016). Samples GQ-12 and GQ-21 are strongly foliated garnet- 3.a. Dorud–Azna area micaschists from the Muteh–Golpaygan metamorphic complex (Fig. 3c, d) and consist of biotite, porphyroblastic garnet (up to The Dorud–Azna region is located in the central part of the SSMZ 1 mm in size), white mica, plagioclase, chlorite and opaque phases. close to the Main Zagros thrust, which is known to comprise a pol- yphase metamorphic succession (Mohajjel et al. 2003; Nutman et al. 2014; Shakerardakani et al. 2015, 2021; Fig. 2b). Structural studies and our previous U–Pb zircon dating work on this area 4. Analytical methods demonstrated three metamorphic units, which are from footwall In this study, we analysed the detrital zircon populations of three to hangingwall (Fig. 2b): (1) the Triassic June Complex, metamor- garnet-micaschist samples from the SSMZ to gain insight into the phosed within greenschist-facies conditions; overlain by (2) the provenance of these strata and how it changes through time and amphibolite-grade metamorphic Pan-African Galeh-Doz orthog- along the SSMZ. Two samples, GQ-12 and GQ-21, were collected neiss, which is intruded by some mafic dykes, and (3) the to the north of the Muteh–Golpaygan metamorphic complex, – Amphibolite Metagabbro unit, which includes Carboniferous while the third sample, LJ-140, was collected northeast of the metagabbro bodies (Shakerardakani et al. 2015; Fergusson et al. Dorud area (Fig. 2b; online Supplementary Material Table S1). 2016), Carboniferous granitic orthogneiss (Shabanian et al. All three samples contain abundant zircon grains. 2020) and undated amphibolites. These units have almost invari- Zircons were extracted from a garnet-micaschist (sample LJ- ably undergone a complex history of repeated shearing, folding and 140) of the Dorud–Azna region at Salzburg University. About transposition of ductile fabrics, which are associated with poly- 3 kg of each sample was crushed in a steel disc mill to obtain phase Jurassic and Cretaceous greenschist- to amphibolite-facies the ~50–250 μm sieve fraction. Zircons were concentrated by a metamorphism. In the eastern part, the overlying low-grade meta- standard plastic pan and warm water, Frantz isodynamic magnetic morphic Triassic sequence is intruded by the Upper Jurassic separator and methylene iodide heavy liquid separation proce- Darijune gabbro (Shakerardakani et al. 2015). dures, and handpicking under a binocular microscope. A total The metapelitic rocks studied in this work occur in several small of 130 zircon grains were dated in situ on an excimer (193 nm – outcrops within the Amphibolite Metagabbro unit in contact with wavelength) laser ablation inductively coupled plasma mass spec- metagabbro over more than 1 km around Dare-Hedavand village trometer (LA-ICP-MS) at the State Key Laboratory of Continental (Fig. 2b). The studied micaschist is brown, exhibits a weak schistos- Dynamics, Northwest University, Xi´an, China. Trace elements ity and consists of garnet, plagioclase, quartz, K-feldspar, biotite were measured simultaneously. The analytical details follow Liu and chlorite (Fig. 3a, b). et al.(2008) and are described in Appendix 1. U–Pb and trace-element analysis of a total of 228 detrital zircon – 3.b. Muteh Golpaygan metamorphic complex grains obtained from two garnet-micaschist samples (GQ-12 and The Muteh–Golpaygan metamorphic complex is located close to GQ-21) within the Muteh–Golpaygan metamorphic complex was the northeastern boundary of the central SSMZ, close to the performed at the China University of Geosciences, Beijing by LA- UDMA within the hinterland of the Zagros orogen (Fig. 2c). ICP-MS, using the methodology of Song et al.(2010). Detrital zir- The Muteh–Golpaygan metamorphic complex is generally con grains (~50–200 μm) were separated from crushed rocks using bounded by NE–SW- to E–W-trending high-angle normal faults a standard plastic pan and warm water and subsequent magnetic

Fig. 2. (Colour online) (a) Main zones under consideration in Iran. (b) Simplified geological map of the Dorud–Azna region and sample location of garnet-micaschist. Ages are given in Ma; sources of data: 1 – Shakerardakani et al.(2015); 2 – Fergusson et al.(2016). (c) Geological map of the Muteh–Golpaygan area and location of investigated samples (modified after Shakerardakani et al. 2020 and references therein). Sources of data: 1 – Shakerardakani et al.(2020); 2 – unpub- lished data; 3 – Hassanzadeh et al. (2008).

Fig. 3. (Colour online) (a, c, d) Field photographs of schist outcrop sampled in the study and (b) representative pho- tomicrograph of schist. (a) Foliated garnet-micaschist in the Dorud–Azna area. Diameter of coin for scale is 29.3 mm. (b) Large garnet porphyroclasts in the matrix composed of quartz, plagioclase, K-feldspar and biotite. (c, d) Strongly foliated garnet-micaschists of the Muteh–Golpaygan area. Length of ham- mer for scale is 33 cm.

separation and heavy liquid separation followed by handpicking. Supplementary Material Table S1). The majority of the zircon pop- The analytical details are given in Appendix 2. ulations (96 %) contain grouping of 565–700 Ma, 737–805 Ma, For interpretation of the age data, we used the recent version 820–915 Ma, 0.93–1.1 Ga, 1.81–2.07 Ga, 2.14–2.5 Ga and one (http://www.stratigraphy.org) of the time-scale calibration pro- younger, Cambrian age (~507 Ma). Owing to low Th/U ratios posed by Cohen et al.(2013). and missing oscillatory zoning, four zircons (507 ± 9 Ma, 586 ± 8 Ma, 692 ± 9 Ma and 702 ± 11 Ma) are interpreted as metamorphic zircons. Only four Archaean ages (<4 %) were discovered 5. Analytical results (~2.62, 2.68, 2.73 and 3.24 Ga). Together, we carried out a coupled U–Pb age and trace-element analysis of 362 detrital zircons from three garnet-micaschist samples (primarily Palaeozoic–early Mesozoic in age, see Sections 5.a 5.b. Detrital zircon ages: Muteh–Golpaygan metamorphic and 5.b) distributed along a ~100 km long section of the central complex SSMZ, and they can be taken as representative of the central part A total of 90 valid age values out of 228 zircon grains were obtained of the SSMZ. based on whether their U–Pb analyses were concordant or not. – Most zircon grains from the sample GQ-21 are euhedral to sub- 5.a. Detrital zircon ages: Dorud Azna area hedral prisms (50 to 150 μm in length) with a clear oscillatory (e.g. Zircons from sample LJ-140 have crystal lengths of ~70 to 200 μm. spot 50) and/or sector zoning (e.g. spots 41, 87) in CL images and Except those with an early Proterozoic age or with an age at the Th/U ratios ranging from 0.11 to 3.13, suggesting that they have a middle/late Proterozoic boundary, most grains are euhedral or magmatic origin (Figs 4, 6). However, nine zircon grains appear subeuhedral, implying relatively short transport. As shown in rep- homogeneous in CL images and were recorded to possess low resentative cathodoluminescence (CL) images (Fig. 4), the majority Th/U ratios of 0.03 to 0.07; these characteristics typically imply of the investigated zircon grains exhibit clear inner structures with a metamorphic origin (e.g. Rubatto, 2002). a broad zoning, an internal oscillatory zoning and very rarely thin Zircon U–Pb analyses yielded diverse age groups, indicating bright rims under CL, interpreted as metamorphic overgrowths. different sources for the zircons (Fig. 5). Six major age populations Zircons have Th and U contents ranging from 2.06 to 1357 dominate the GQ-21 detrital zircon grains, with populations at ppm and 34.21 to 2618 ppm, respectively. The Th/U ratios range 547–611 Ma, 642–788 Ma, 868–931 Ma, 0.97–1.17 Ga, 1.79– from 0.10 to 1.78 with a mean value of 0.53, except four spots (Th/ 2.07 Ga and 2.36–2.5 Ga. From a total of 40 dated subconcordant U <0.1), indicating that the majority of the zircons are of magmatic zircons, one gave an Ordovician age (~467 Ma), two gave origin (Corfu et al. 2003; Corfu, 2004). Cambrian ages (~505 Ma, 532 Ma) and one gave a Neoarchaean In total, 134 analyses were obtained for 130 zircon grains from age (~2.58 Ga; online Supplementary Material Table S1). Six the garnet-micaschist sample; 30 analyses are not considered Proterozoic zircons (1787 ± 35 Ma, 1030 ± 52 Ma, 642 ± 4 Ma, because of a discordance of >10 %, and 104 grains are subconcord- 611 ± 5 Ma, 602 ± 5 Ma, 552 ± 4 Ma) are considered to have a ant between 90 and 110 % concordancy (Fig. 5; online metamorphic origin.

Fig. 4. Cathodoluminescence images of dated zircons from garnet-micaschists of the Dorud–Azna and Muteh–Golpaygan regions. 206Pb–238U age (Ma) is shown for ages <1000 Ma, the 207Pb–206Pb age when older than 1000 Ma. Circles represent analysis spot positions with spot numbers and their ages in Ma.

With the exception of few sub-rounded zircon grains in sample The Th/U ratios of the zircons range from 0.10 to 2.03, except four GQ-12, the vast majority of the zircons are nearly euhedral or sub- spots (<0.1). The U and Th concentrations range from 75.5 to 2759 hedral and prismatic (~50 to 100 μm in length). Many zircons ppm and from 18.21 to 2218 ppm, respectively. show a clear oscillatory or sector zoning in CL images, and some The zircon age populations from sample GQ-12 span character- of them exhibit thin overgrowth rims of weak or no zoning (Fig. 4). istic intervals of time, namely 200–323 Ma, 383–423 Ma, 559–

Fig. 6. (Colour online) Zircon Th/U ratio versus U–Pb ages of the detrital zircons from three garnet-micaschists. Note that most of the zircons from this study reside above 0.1.

5.c. Trace-element chemistry of the zircons Trace-element compositions of zircon grains can identify the most likely source rock types within which the detrital zircon grains crystallized (e.g. Belousova et al. 2002; Hoskin & Schaltegger, 2003; Grimes et al. 2007, 2015; Portner et al. 2011; Ranjan et al. 2020). Chondrite-normalized rare earth element (REE) patterns (online Supplementary Material Table S2; Fig. 7) for most of the laser spots of sample LJ-140 indicate features typical for a wide variety of crustal rocks (Hoskin & Schaltegger, 2003), with heavy rare earth element (HREE) abundance between 100× and 10 000× chondrite. Spider plots show prominent positive and negative Ce and Eu anomalies, respectively (Fig. 7). The REE patterns, zircon internal textures and high Th/U ratios (Th/U = 0.1–1.78) suggest that a majority of the zircons are typical of magmatic protoliths with mild effects of late-magmatic/metamorphic recrystallization, as indicated by the flat HREE patterns for a few zircons (Fig. 7). The chondrite-normalized zircon REE patterns for all age populations of sample GQ-21 show a similar pattern of depleted light rare earth elements (LREEs), progressively increasing HREEs, a prominent positive Ce anomaly and a negative Eu anomaly. These observations are consistent with the textural features indicating zircon growth from melts as a dominant process for the growth of all zircon populations (Rubatto & Hermann, 2007). Discrimination diagrams using U/Yb or Th/Yb ratios provide a robust method for distinguishing modern zircons crystallized within continental or oceanic crust (Grimes et al. 2007, 2015). Generally, the U/Yb ratio is controlled by the difference in element solubility. Incompatible elements, such as U, are readily soluble in fluids and thus subsequently enriched in continental crust relative to oceanic crust and upper mantle (Grimes et al. 2007). Fig. 5. (Colour online) Histograms and Kernel Density Estimations (KDE) for detrital Consequently, continental crust is less enriched in incompatible zircon U–Pb ages in the studied samples. (a) Sample from the Dorud–Azna region and elements, such as Y and Yb, relative to oceanic crust (e.g. (b, c) Samples from the Muteh–Golpaygan region of the central Sanandaj–Sirjan meta- Belousova et al. 2002; Grimes et al. 2007). On the U/Yb versus morphic zone. Hf (and U versus Yb) diagrams, the detrital zircons in both samples plot predominantly in the field of continental zircons; based on available data they are clearly distinct from the field of oceanic 626 Ma, 808–963 Ma and 1.81–2.5 Ga, displaying a multi-peaked crustal zircons (Fig. 8a, b). Furthermore, Grimes et al.(2015) have age distribution pattern (Fig. 5). Five out of 50 subconcordant zir- shown that the Nb/Th and Nb/U ratios of zircons reflect the ratios cons analysed have Jurassic (~149–200 Ma) ages. This sample yields of their host rocks and that zircons from continental arcs have a small portion (<4 %) of metamorphic zircons (1916 ± 24 Ma, 1808 lower Nb/Th and Nb/U ratios compared to zircons in rocks from ± 21 Ma). non-arc settings. Plotting the detrital zircons shows that nearly all

Fig. 7. Chondrite-normalized REE patterns for zircons from sample LJ-140. Chondrite data are from McDonough & Sun (1995).

of the detrital zircon populations (92–95 %) are enriched in U/Yb weighted mean age of the youngest age peak from an at least three- ratios and plot in the continental field (Fig. 8a–c). This result can- grain cluster with overlapping ages within the 2σ error and a mean not be attributed to a homogeneous source region or derivation of square weighted deviation (MSWD) ≤1; and (4) the weighted aver- detritus from a single source but was considered by Hoskin & age age of the youngest two or more grains that overlap in age at Ireland (2000) to confirm the apparent monotony of REE patterns 1σ error. and abundances in zircons derived from a range of common The oldest sample in this study (sample LJ-140) was collected crustal rock types (Hoskin & Schaltegger, 2003). from the north of the Dorud–Azna region in the central SSMZ (Fig. 2b). The sample displays a prominent peak at 577 ± 9 Ma, which is only ~10 Ma younger than the Cadomian orthogneiss 6. Discussion basement and which is in close contact with the sample 6.a. Depositional ages (608 ± 18 Ma and 588 ± 41 Ma; Shakerardakani et al. 2015) implying a tectonic contact between these two lithologies. This 577 Ma In order to determine the most reliable maximum depositional age age provides the maximum depositional age for this unit. A grain for each sample, we utilize four alternate measures of the maxi- with an age of 507.1 ± 9.41 Ma possesses a low Th/U ratio of <0.1 mum depositional ages as outlined by Dickinson & Gehrels indicating metamorphic growth, which could be post-depositional. (2009). These include: (1) the age of the youngest single grain σ East of the oldest sample from the central SSMZ, close to the within a sample with a 1 error less than 10 Ma (e.g. Stevens UDMA, two samples (GQ-21 and GQ-12) were collected from Goddard et al. 2018); (2) the youngest graphical peak detrital zir- the Muteh–Golpaygan metamorphic complex. The first sample con age controlled by more than one grain age; (3) the calculated

Fig. 7. (Continued) Chondrite-normalized REE patterns for zircons from sample GQ-21. Chondrite data are from McDonough & Sun (1995).

(sample GQ-21) is distinguished by its prominent peak near 561 LJ-140 from the Dorud–Azna region. The youngest single grain Ma, but it also contains one Middle Ordovician (467 ± 8 Ma) yielding an age of 467 ± 8Ma(1σ), however, may indicate a youn- and two Cambrian (505 ± 4 Ma, 532 ± 4 Ma) detrital zircon grains. ger depositional age. The weighted mean age for four grains at the prominent peak men- The second sample from the northwestern part of the Muteh– tioned above is 552 ± 4 Ma (MSDW = 0.69). The ~552 Ma age Golpaygan complex (GQ-12) displays a marked change in prov- peak for sample GQ-21 is close to the 577 Ma peak of sample enance to Mesozoic–Palaeozoic sources with main peaks at

230 Ma, 404 Ma, 609 Ma and 1867 Ma (Fig. 5). The youngest peak in this sample is at the Late Triassic – Early Jurassic boundary (205 ± 5 Ma; MSDW = 1.9), and only three zircons are distinctly younger (149 ± 2 Ma, 158 ± 3 Ma and 168 ± 3 Ma) than the rest (>190 Ma). We assume therefore a maximum depositional age of earliest Jurassic for this sample, which is reasonable as metamorphosed Jurassic sediments are widespread within the central SSMZ and represent the metamorphosed cover on the Cadomian basement (e.g. Rachidnejad-Omran et al. 2002; Sheikholeslami et al. 2003; Fazlnia et al. 2007; Davoudian et al. 2016). As geochronology constrains the age of metamorphism to the Late Jurassic period (156 Ma; Rachidnejad-Omran et al. 2002), the depositional age is within the short period between 205 and 156 Ma.

6.b. Provenance 6.b.1. Magmatic history of the SSMZ Previous studies have provided a wealth of isotopic age constraints for many of the regional and long-lived magmatic events in the SSMZ (Hassanzadeh & Wernicke, 2016). Although Palaeozoic magmatic rocks are rare in Iran, compared to abundant Mesozoic and Cenozoic magmatism, they record multiphase magmatism during Ordovician–Silurian, Devonian–Carboniferous and Permian times (e.g. Berberian & King, 1981; Hassanzadeh & Wernicke, 2016; Moghadam et al. 2020a), suggesting major tectonic events related to the formation of the Palaeotethyan and Neotethyan oceans. Sample GQ-12 from the northwestern Golpaygan area includes the youngest detrital zircon grains with Proterozoic, Devonian, Carboniferous, Permian and Late Triassic ages. In particular, the Late Triassic U–Pb ages of 205 to 233 Ma are prominent. Sample GQ-21 from the same area yielded grains as young as 467 Ma and lacks significant Carboniferous, Permian and Late Triassic age groups, but bears a significant Neoproterozoic age population. The continental crust of the SSMZ was thinned during Permian and Triassic times (e.g. Zanchi et al. 2009a,b;Buchset al. 2013; Hassanzadeh & Wernicke, 2016; Shakerardakani et al. 2018). This precludes the possibility that the Late Triassic zircons are of xenocrystic origin through crustal contamination during the ascent of basaltic magmas through the continental crust of the SSMZ. As suggested by Shakerardakani et al.(2018), this basaltic magmatism may have originated from hotspot magmas intruding into the crustal base of the thinned Sanandaj–Sirjan passive margin basement and rising up into shallow levels. The latest Triassic/earliest Jurassic maximum depositional age of sample GQ-12 corresponds in age with the Middle–Upper Triassic to Jurassic sedimentary rocks, which were deposited on the passive continental margin of the Neotethys Ocean (Hassanzadeh & Wernicke, 2016; Shakerardakani et al. 2018). On the other hand, an origin of Triassic zircons from Late Triassic granites of Central Iran cannot be excluded (e.g. Ramezani & Tucker, 2003). Abundant similar Early Triassic to Permian ages were recently reported by Meinhold et al.(2020)from Fig. 8. (Colour online) (a, b) U/Yb versus Hf and U versus Yb concentrations in zircon Triassic sandstones of Central Iran. and expected generalized trends for zircon from variably incompatible element- Furthermore, two Carboniferous–early Permian age peaks were enriched reservoirs as well as parental melt fractionation (Grimes et al. 2015). The field recorded for zircons of sample GQ-12, matching the modal age of labelled ‘Continental Survey’ and lower bound were defined by Grimes et al.(2007). (c) U/Nb proxy for the tectono-magmatic source of igneous zircon. The shaded band rep- extensive Carboniferous and earliest Permian granite-gabbro resents a ‘mantle-zircon array’ defined by Grimes et al.(2015). The upper boundary is intrusive suites appearing both in the SSMZ and Central Iran, as placed at the Nb/Yb, U/Yb endpoints (0.0004, 0.02) and (1, 10). Magmatic arc and post- well as in the Alborz Mountains and NE Iran (e.g. Bagheri & collisional continental zircon are typically offset above the mantle-zircon array. Stampfli, 2008; Zanchi et al. 2009a,b; Zanchetta et al. 2009, – NMORB normal mid-ocean ridge basalt. 2013; Bea et al. 2011; Buchs et al. 2013; Saccani et al. 2013;

Kargaranbafghi et al. 2015; Moghadam et al. 2015; Shakerardakani (Gehrels, 2014). The palaeogeographic relationships of the et al. 2017; Honarmand et al. 2017; Shabanian et al. 2020). Late SSMZ are usually considered to relate to the Arabian–Nubian Palaeozoic rifting of the future Neotethys Ocean formed ribbon shield with its Neoproterozoic magmatic arcs and back-arc com- continental fragments in Iran that broke away from the northern plexes. Particularly interesting are the age groups of 740–760 Ma margin of Gondwana (e.g. Berberian & King, 1981; Şengör, 1990; and around 826 Ma. Based on our new U–Pb zircon ages, we dis- Agard et al. 2011; Richards, 2015). Subsequently, after a long cuss here two potential relationships: (1) the Arabian–Nubian period of epeirogeny and significant breaks in the sedimentary rec- shield connection and (2), as an alternative, which is also sup- ord during Ordovician–Carboniferous times, the late ported by biogeographic relationships, the South China block con- Carboniferous to early Permian was a period of marine transgres- nection. For comparison, age spectra of these regions are shown in sion associated with a major extensional phase that affected most Figure 9. parts of Iran (Berberian & King, 1981; Alavi-Naini, 2009). The available source for the early Permian zircons (sample GQ- 6.b.2.a. Correlation of Gondwanan detrital zircon age spectra. 12) is dominated by the isolated early Permian anorogenic The age population clusters at 0.55–0.63 Ga, 0.64–0.78 Ga, 0.80– Hasanrobat pluton (294–288 Ma), which is located south of the 0.91 Ga, 0.94–1.1 Ga, 1.8–2.0 Ga and 2.1–2.5 Ga are present in Muteh–Golpaygan metamorphic complex and intruded into upper nearly all samples (Fig. 5). The percentage of >540 Ma zircons Carboniferous – lower Permian strata (Alirezaei & Hassanzadeh, in each sample generally decreases with younger stratigraphic ages, 2012; Honarmand et al. 2017). The Carboniferous ages of detrital ranging from ~96 % in the oldest sample to <25 % in the youngest zircons can be explained by subordinate granitic orthogneisses and samples. A comparison of the Neoproterozoic and early Palaeozoic metagabbros of the region (Shakerardakani et al. 2015; Fergusson detrital zircon age spectra has important implications for the palae- et al. 2016; Shabanian et al. 2020). otectonic reorganization at the Gondwana margin. Our data show Vestiges of volcanic activity during Devonian time, mostly a significant concentration of detrital zircons at 0.55–0.63 Ga, con- restricted to sill-like intrusions, dykes and lava flows interlayered sistent with ages of widespread Pan-African subduction-related within sedimentary formations, are particularly known in Alborz, granitic basement in Iran (e.g. Ramezani & Tucker, 2003: Central Iran, the SSMZ, and NE and NW Iran (e.g. Assereto, 1963; Hassanzadeh et al. 2008; Nutman et al. 2014; Shakerardakani Alavi & Bolourchi, 1973; Lammerer et al. 1984; Houshmandzadeh et al. 2015; Moghadam et al. 2018). et al. 1990; Wendt et al. 2002, 2005; Derakhshi & Ghasemi, 2015; The age groups of c. 0.6–0.9 Ga compose ~35 % of all analysed Ghasemi & Dayhimi, 2015). Early Devonian detrital zircons can be zircons of samples LJ-140 and GQ-21. Based on ion-microprobe traced from intra-oceanic Palaeotethys subduction and U–Pb analyses of detrital zircon grains from various continental-type magmatism (e.g. Ghazi et al. 2001; Zanchetta Neoproterozoic to Cambrian sandstones of the Alborz and et al. 2013; Moghadam et al. 2017). The Early Devonian age pop- Zagros mountains and from the basement of the Central Iranian ulation of the Golpaygan detrital zircons is scattered around plateau, Horton et al.(2008) proposed that a basal clastic succes- 404 Ma, but it is unlikely that such zircons could be transported sion representing the earliest sedimentary record in Iran displays a from NE and NW Iran across the Palaeotethys to be deposited provenance age signature dominated by Pan-African (0.9–0.6 Ga) in the future SSMZ (Moghadam et al. 2017). Paidar-Saravi rocks, which are similar to detrital zircon age spectra for age-equiv- (1989) described a range of different metavolcanic rocks, including alent units of the west and south in Israel, Jordan, Egypt and Saudi rhyolitic, dacitic and andesitic lava, which are interlayered with Arabia in northern Gondwana (e.g. Avigad et al. 2003, 2015, 2017; schists in the Muteh–Golpaygan metamorphic complex. Kolodner et al. 2006; Meinhold et al. 2021). Because of the lack of Rachidnejad-Omran et al.(2002) also mentioned the presence significant pre-600 Ma detrital zircon ages, these authors have of metarhyolite and metavolcanic tuff. They suggested that meta- therefore concluded that the main sources were likely located in rhyolites together with amphibolites represent a bimodal volcanic Pan-African basement provinces of Arabia and Africa, particularly suite and, together with the host schist and gneiss, an early in the Arabian–Nubian shield, although the Iranian basement may Palaeozoic volcano-sedimentary complex. Our field observations have contributed some sediment. In addition, Moghadam et al. show that the undated rhyolitic rocks are interlayered within a (2017) suggested that the 0.6–0.5 Ga old detrital zircons belong Devonian–Carboniferous unit including marble, slate and meta- to the local Cadomian magmatism in Iran and surroundings or, sandstone and are located in close contact with schists, orthog- alternatively, to the Arabian–Nubian shield and other reworked neisses and amphibolites in the central part of the Muteh– continental crust of Gondwana. Golpaygan metamorphic complex. Therefore, we conclude that Pre-Neoproterozoic zircons, grouped at c. 0.9–1.1 Ga Early Devonian detrital zircons have mostly local sources. (Grenvillian), c.1.8–2.0 Ga (early Proterozoic A) and c. 2.1– The same is true for the ages around 600 Ma, which are well 2.5 Ga (early Proterozoic B) make up nearly 35 % of the total zircon known in Palaeozoic and Mesozoic sediments and Precambrian ages. For the Palaeoproterozoic zircons, there is a plausible origin magmatic basement rocks in the SSMZ and Central Iran (e.g. from the Arabian–Nubian shield and Africa with a juvenile mantle Ramezani & Tucker, 2003: Hassanzadeh et al. 2008; Nutman source (Honarmand et al. 2016; Moghadam et al. 2017). Variable et al. 2014; Shakerardakani et al. 2015; Moghadam et al. 2018, amounts of ~980 Ma ages also occur in Palaeozoic sedimentary 2020b; Meinhold et al. 2020). rocks of Saudi Arabia (Meinhold et al. 2021), and the Consequently, age populations older than c. 600 Ma are distinc- Grenvillian population of our samples might have their source tive for the derivation of the SSMZ. there. The Grenvillian detrital zircons first appear in the Alborz and Zagros succession in the upper Neoproterozoic to 6.b.2. Palaeogeographic relationships of the SSMZ Cambrian formations (Horton et al. 2008). Zoleikhaei et al. Detrital zircon geochronology has been widely used as a robust (2020) recently found a minor population peak at ~980– method with which to identify the source of sedimentary rocks 1015 Ma in the Cambrian sandstones of the central Alborz. (Gehrels, 2014). It also represents a powerful means of resolving Nutman et al.(2014) reported a similar age group of 0.9–1.0 Ga the displacement history of potentially displaced terranes with juvenile initial ϵHf values in inherited zircon cores of some

Fig. 9. (Continued)

Pan-African granitoids in a nearby region of Dorud within the central SSMZ. The provenance of the Grenvillian-age zircons in Central Iran was interpreted as being involved in crustal evolution in an island arc setting, continuing in an active continental margin (Honarmand et al. 2016). In NE Iran, it was suggested that detrital zircons belonging to the Grenvillian-age cluster at c. 1020 Ma might be derived from a basement like that found in a sliver of Fig. 9. Compiled histogram and Kernel Density Estimate (KDE) of pre-460 Ma to 1400 Ma detrital zircon U–Pb ages from clastic sediments of the (a) Sanandaj– Sinai basement rocks or lower Palaeozoic sandstones from Libya Sirjan metamorphic zone, and (b) Alborz Mts, Central Iran and NE Iran. (c) and Jordan (Be’eri-Shlevin et al. 2012; Moghadam et al. 2017). Histograms showing the magmatic age distribution in the South China block The distribution of c. 1.0 Ga detritus (Meinhold et al. 2013) was and (d1) in the Arabian–Nubian shield and its latest Neoproterozoic cover. (d2) used for the palaeogeographic reconstruction of fragments rifted Histogram for detrital zircon U–Pb age distribution for Neoproterozoic– Cambrian sedimentary units within the Arabian–Nubian shield. Data sources: (a, from Gondwana during Palaeozoic and Mesozoic times. This b) Shakerardakani et al.(2019 and references therein); Meinhold et al.(2020); led to the division of the North African margin of Gondwana, Zoleikhaei et al.(2020). (c) Condon et al.(2005); Liu et al.(2008); Compston on the basis of zircon age data from Cambrian sandstones, into et al.(2008); Dong et al.(2012); Charvet (2013); Zhao et al.(2013); Wang et al. two separate domains comprising an eastern domain containing (2013); Li et al.(2014 and references therein); Yao et al.(2014); Du et al.(2014); 1.0 Ga detrital zircons and a western domain practically devoid Okada et al.(2014); Lan et al.(2015 and references therein); Yang et al.(2016 and references therein); Yang et al.(2017 and references therein); Lan et al. of c. 1.0 Ga detrital zircons (Meinhold et al. 2013). The age popu- (2017); Wang et al.(2018, 2019, 2020). (d1) Hedge (1984); Pallister et al.(1988); lation of 1.0 Ga, which is rare in western North Africa (Algeria, Stern (1994); Andersen et al.(2009); Bea et al.(2009); Be’eri-Shlevin et al.(2009); Morocco), is more common in the east (Libya, Israel, Jordan), Ali, B. H. et al.(2009); Ali, K. A. et al.(2009, 2010, 2014, 2015); Kennedy et al. where it was supplied with detritus from the Transgondwanan (2010, 2011a,b); Morag et al.(2011); Johnson et al.(2011 and references therein); Augland et al.(2012); Johnson et al.(2013); Robinson et al.(2014); Yeshanew et al. Supermountain via the Gondwana superfan system (Squire et al. (2015); Hassan et al.(2016); Kozdr´oj et al.(2018 and references therein); Cox et al. 2006; Meinhold et al. 2013; Neubauer, 2014). (2019); Ghanem et al.(2020); Abbo et al.(2020); Khudeir et al.(2021). (d2) Avigad In summary, it can be concluded that the Neoproterozoic detri- et al.(2003); Morag et al.(2012); Li et al.(2018); Abd El-Rahman et al.(2019); tal zircons from the studied schist samples of the SSMZ could have Meinhold et al.(2021). their origin in the Arabian–Nubian shield. In the further

discussion, we examine potential relationships to blocks further and Central Iran terranes of Iran, as well as the Central Afghan east, particularly to the South China block. terranes and part of the Pamirs, Qiangtang, Lhasa and the The South China block was formed by amalgamation of the Tibetan Himalaya of the Tibetan Plateau, and Sibumasu in south- Yangtze and Cathaysia blocks at c. 0.85 Ga, followed by anoro- east Asia (e.g. Stern, 1994; Torsvik & Cocks, 2013; Yao et al. 2014; genic, rift-related magmatism at c. 820–740 Ma, centring around Domeier, 2018). In regard to most palaeogeographic reconstruc- 850, 820, 800, 780 and 750 Ma, that are coeval with the break- tions, a position of the South China block within the tropical zone up of the Rodinia supercontinent (e.g. Li et al. 2008;Liet al. of western Gondwana during early Cambrian time is indicated 2009, 2014; Yao et al. 2014; Shu et al. 2021). As suggested by (Kirschvink, 1992; McKerrow et al. 1992). Biogeographic studies Yao et al.(2014; Fig. 9) and discussed in detail by Li et al. of the lower Cambrian on the Yangtze Platform of the South (2014), the South China block was most likely an integral part China block indicate close relationships with regions of the western of Gondwanaland during early Palaeozoic time, which matches margin of Gondwana, in particular with the Tarim Platform, India the palaeomagnetic analysis (Zhang, 2004) and recent plate tec- and Iran and less similarities to Kazakhstan, Australia and parts of tonic reconstructions (Merdith et al. 2021). Available geological West Avalonia (Steiner et al. 2007). data shows that the South China block has a great affinity with The palaeogeographic evidence of the Toyonian archaeocya- India or Australia. However, the exact position of the South than reefs in the Alborz Mountains indicates the first record of China block in Gondwana has not been well constrained. For metazoan reefs in the Toyonian (Cambrian Stage 4) of Iran and instance, detrital zircon age patterns indicate that the South adjacent countries (Lasemi & Amin-Rasouli, 2007). Metazoan reefs China block was either adjacent to northern India (Li et al. spread along the northern margin of Gondwana, arguing for a 2014; Yao et al. 2014) or between India and Australia (Yu et al. common Gondwanan margin, and worldwide, such as Siberia, 2008; Wang et al. 2010; Duan et al. 2011; Cawood et al. 2013). eastern Canada and Nevada, through the rest of early Cambrian Furthermore, the presence of the c. 533 Ma metamorphic event time (e.g. James & Kobluk, 1978; James et al. 1988; Rowland & documented in the hornblendite in Cathaysia indicates that the Gangloff, 1988; Rowland & Shapiro, 2002). South China block preserves the record of a major Pan-African Hamdi et al.(1995) suggested that the middle and upper orogeny, supporting the South China block being an integral part Cambrian reefs in the Mila Formation of the Alborz Mountains of the Gondwana assembly (Li et al. 2017). More significantly, it contain a similar sponge genus to that found in the lower middle can help to constrain the location of the South China block in Cambrian of Australia, the Yangtze Platform in the South China Gondwana, suggesting that the South China block (together with block and the Siberian Platform. Kruse & Zhuravlev (2008) elab- Indochina) was most likely connected to northern India by a ‘Pan- orated on this hypothesis by suggesting that the Iranian microcon- African’ collisional orogeny (Li et al. 2014). Recently, Yang et al. tinent was located along the ‘western’ Gondwana margin adjacent (2020) found pronounced Neoproterozoic and Cambrian detrital to other central and SE Asian fragments, Arabia, Tibet, India and zircon age populations from Ediacaran to Cambrian sandstones of South China. the South China block and interpreted these as evidence for amal- More recently, Shahkarami et al.(2017a,b) outlined four ichno- gamation and collision of the South China block with Gondwana. zones for the clastic sediments of the Soltanieh Formation in the These authors also noted the similarity of the South block patterns central Alborz Mountains, indicating continuous sedimentation to those of Iran (Fig. 9). from Ediacaran through Cambrian times. These authors argued Taken together, the Arabian–Nubian shield is often referred to that ichnozone 1 in the Alborz Mountains is evidenced by the as the greatest potential source for the major Precambrian– Treptichnus pedum zone, which is the index fossil for the lower- Palaeozoic detrital zircons in the Iranian microcontinent (e.g. most Cambrian. This reveals a similar situation for the Moghadam et al. 2017; Zoleikhaei et al. 2020). However, we note Ediacaran–Cambrian succession of the Alborz Mountains and that the Iranian microcontinent and South China block may have eastern Yunnan Province, South China (Zhu, 1997), western been geographically close, sharing a similar palaeoenvironment on Mongolia (Smith et al. 2015), Lesser Himalaya, India (Singh the northern Gondwana margin. et al. 2014) and southern Kazakhstan (Weber et al. 2013), where the first appearance of the trace fossil T. pedum post-dates the 6.b.2.b. Palaeobiogeographic arguments. The late Ediacaran–Cambrian transition. Similarly, Hamdi et al.(1989) Neoproterozoic to early Palaeozoic palaeobiogeographic patterns found evidence of an assemblage of phosphatic layers in the provide further important constraints on the relative position of Lower Shale Member in the Alborz Mountains and pointed out the Iranian microcontinent on the northern Gondwana margin. the similarities with successions containing a major Tommotian As mentioned before, the SSMZ, Central Iran and (southern phosphorite horizon nearly contemporaneous across the and central) Alborz are considered to have been part of the ‘Proto-/Palaeotethyan’ belt in South China, India, Pakistan, Iranian microcontinent with the Palaeotethys Ocean in the north Kazakhstan and Mongolia. and the Neotethys Ocean in the south during late Palaeozoic to The new late Cambrian species of Siphonotretida recognized in Mesozoic times. They bear similar upper Ediacaran to the Alborz is the only known Cambrian representative of the group Ordovician, Permian and Triassic strata (Hassanzadeh & with distinct characteristics (Popov et al. 2009a), different from Wernicke, 2016). We give details in the following discussion of other siphonotretide genera, e.g. on both sides of the lapetus two scenarios, the classical one (based on Torsvik, 1998; Ocean in Laurentia and Gondwana (Armorica), and in west Fig. 10a) and an alternative scenario, in which the South China Antarctica (Shergold et al. 1976; Popov et al. 2002; González- block is attached to Gondwana, according to the recent findings C´omez, 2005). The unique features of the late Cambrian of Yang et al.(2020;Fig.10b), but on the same latitude. Siphonotretida of Iran are also characteristics of most of the The principal terranes that are confirmed or commonly Ordovician siphonotretide genera, which likely were rooted origi- assumed to be placed close to the northeastern to northern margin nally in high to temperate latitudes of peri-Gondwana (Fig. 10; of Gondwana in early Palaeozoic time include the SSMZ, Alborz Havlíček, 1982; Mergl, 2002; Popov et al. 2008). Popov et al.

Fig. 10. (Colour online) (a) Palaeogeographic reconstruction for the late Tremadocian–Floian stages showing the geographic distribution of rhynchonelliformean brachiopod genera (from Popov et al. 2009a, based on Torsvik, 1998), which occur in the lower part of the Lashkarak Formation (modified from Torsvik, 1998 and Ghobadi Pour, 2006). Note the potential close neighbourhood of South China and Central Iran/SSMZ at similar latitudes assuming that the units could be freely shifted along latitudes (because of the unde- termined longitude). (b) This reconstruction according to Yang et al.(2020) puts the South China block in East Gondwana. Red double arrow indicates the palaeobiogeographic relationships.

(2013) suggested that it can be typified by those described from the palaeogeographic and climatic control on their initial divergence. Middle Ordovician of Baltica (Gorjansky, 1969; Holmer, 1989) and These authors suggested that the Australasian (Sibumasu) sector of South China (Zhang, 1995). Gondwana was the primary location of the origin and initial Dong et al.(2004) discussed 13 middle Cambrian through dispersion of the Strophomenoidea, as well as the adjacent terranes lowermost Ordovician conodont zones in Hunan, South China and satellite plates of peri-Gondwana, including Alborz, North and their similarities with Iran (Müller, 1973) and correlated these China and South China (Popov & Cocks, 2017). with North China, western USA, western Newfoundland and The first occurrence of Late Ordovician trilobites from the High Canada. In addition, the Early–Middle Ordovician palaeobiogeo- Zagros, has been reported in the middle member of the Seyahou graphic patterns of the brachiopod faunas from the Upper Yangtze Formation (Ghobadi Pour et al. 2015a). This formation hosts a tri- Platform, South China were documented (Zhan & Jin, 2014), indi- lobite assemblage including Dalmanitina (Dalmanitina) dargazen- cating a close faunal relationship between South China and Iran sis, which shows strong affinities with high-to-mid-latitude peri- (Popov et al. 2009b). Gondwanan faunas, and displays close similarities with taxa from The Lower Ordovician (Tremadocian) trilobite assemblage, as the Mediterranean margin of Gondwana (mainly Sardinia and well as Darriwilian brachiopods in the Alborz, exhibit a close sim- Bohemia/Perunica) and, to a lesser extent, with the Turkish ilarity to contemporaneous trilobite faunas of South China (e.g. Taurides (Ghobadi Pour et al. 2015a). Ghobadi Pour, 2006; Ghobadi Pour et al. 2007, 2011; Álvaro Ameri (2015) reported a peri-Gondwanan trilobite assemblage et al. 2013; Kebria-ee Zadeh et al. 2015). Ghobadi Pour et al. from the Kuhbanan Formation at Dahu, north Kerman, which is (2007) noted the species Taihungshania miqueli (Bergeron, the most complete fossiliferous upper lower Cambrian – middle 1894), the third diagnosable species, which has been recorded from Cambrian sequence in Central Iran. The distribution of the South China, Turkey and Southern France, indicating North Kuhbanan Formation trilobite species (Redlichia Biozone) shows Gondwanan faunal affinities. In the eastern Alborz (Gerd-Kuh sec- close faunal connections to the Hormoz Formation from South tion), the lower Tremadocian Asaphellus inflatus–Dactylocephalus and SW Iran, the Salt Range (Pakistan), the Himalayan region, and Psilocephalina lubrica zones are characterized by medium southern Siberia, Australia and South China (Ameri, 2015). diversity trilobite associations with strong links to contemporane- Popov et al.(2014) reported an important record of biotic ous faunas of South China (Ghobadi Pour et al. 2015b). In addi- recovery of benthic faunas in the Llandovery deposits of Iran after tion, abundant and diverse brachiopods are present throughout the terminal Ordovician mass extinction in temperate and high lat- the Gerd-Kuh section, and, as Popov & Cocks (2017) pointed itude Gondwana, which is still poorly known in the Mediterranean, out, Alborz is one of the few places globally which has a stropho- North African and Arabian segments of Gondwana. A significant menoid-dominated benthic assemblage in the Middle Ordovician number of taxa from the shallow shelf biofacies indicates clear links brachiopod fauna, providing the opportunity to investigate the to contemporaneous low-latitude faunas, for instance to Laurentia,

Fig. 11. (Colour online) Global reconstruction for the earliest Cambrian (540 Ma), showing the location along Gondwana of the blocks (modified after Torsvik & Cocks, 2013 and Yao et al. 2014). The red arrows point to the biogeographic and detrital zircon provenance relationships in the reconstruction. West and East Gondwana are separated by the Transgondwanan Supermountain. A – Afghan Terrane; ATA – Armorican Terrane Assemblage; E – Ellsworth-Whitmore Mountains; F – Falkland Islands; MBL – Marie Byrd Land; NZL – New Zealand; Qiang. – Qiantang Terrane; SSMZ – Sanandaj–Sirjan metamorphic zone; TH – Tethyan Himalaya.

Baltica and South China (Popov et al. 2014). The authors proposed sediments not older than latest Triassic, consistent with the the close proximity of the peri-Gondwanan terranes of Central metamorphosed Jurassic sediments widespread within the Iran, Kopet Dagh and Afghanistan, owing to the bearing of shallow central SSMZ. water faunas during the Aeronian of the Silurian period. (2) The reproducibility is remarkable of the age population peak at In summary, late Neoproterozoic to the early Silurian faunas, c. 0.6 Ga, which represents a distinct signal related to the late restricted to the same type of palaeoenvironment, are shared by Neoproterozoic crystalline basement in Iran as well as to the the Iranian microcontinent and South China block and represent Arabian–Nubian shield and other Pan-African domains in key elements to determine their palaeogeographic similarities northern Gondwana. The other significant Neoproterozoic along the Gondwanan margin (Figs 10, 11). Li et al.(2014) and age populations in all three samples likely derived from mag- Yang et al.(2020) proposed that the South China block was matic rocks and/or recycled sedimentary sources, possibly accreted to East Gondwana during late Neoproterozoic– from the eastern Arabian–Nubian shield. Cambrian times. Consequently, the Iranian microcontinent (3) New zircon age data from garnet-micaschists demonstrates the including the SSMZ can be considered as being part of the same presence of a late Grenvillian age population at c. 0.94 to 1.1 Ga Cambrian–early Silurian Gondwanan margin. Comparison of within the SSMZ, which led to deducing the proximity of the detrital zircons show similar age patterns in terranes originating Sanandaj–Sirjan zone to distal parts of the ‘Gondwana super- from north of the Arabian–Nubian shield via the Iranian micro- fan’ at the northern margins of Gondwana. The Grenvillian continent to far in the east, along the northern Gondwana margin detrital age population suggests that the ‘Gondwana superfan’ (Fig. 11). even spread detrital material far east along the northern Gondwana margin and reached the South China block, where this age group occurs but remains subordinate (e.g. Yang et al. 7. Conclusions 2020). (4) It is worth noting that further research should focus on more – New detrital U Pb zircon ages from the SSMZ provide new detrital zircon ages from metamorphic clastic rocks and insights into the palaeogeographic reconstruction of the Iranian Cambrian–Ordovician sandstones as well as obtaining the bio- microcontinent. Our conclusions are summarized as follows: geographic distribution of Cambrian–Ordovician shallow marine organisms that would also provide better insights into (1) The youngest peak and weighted mean ages in the probability the palaeogeographic reconstruction of the northern diagrams provide geochronological maximum depositional Gondwana margin during early Palaeozoic time. ages for hitherto undated metamorphic units. In particular, detrital zircon ages from the younger garnet-micaschist sam- Supplementary material. To view supplementary material for this article, ple (GQ-12) represent a maximum depositional age of the please visit https://doi.org/10.1017/S0016756821000728

Acknowledgements. We gratefully acknowledge constructive comments and Ameri H (2015) Peri-Gondwana Late Early–Middle Cambrian trilobites from suggestions from two anonymous reviewers, which helped to clarify ideas and the Kuhbanan Formation in Dahu section, Kerman Province, Iran. Arabian content. We also thank the editor, Olivier Lacombe, for his encouragement. Journal of Geosciences 8, 1467–78. Farzaneh Shakerardakani acknowledges support via a scholarship from the Andersen A, El-Rus MMA, Myhre PI, Boghdady GY and Corfu F (2009) U– Afro–Asiatisches Institut Salzburg for her Ph.D. thesis at the Salzburg Pb TIMS age constraints on the evolution of the Neoproterozoic Meatiq University, and a PIFI postdoctoral fellowship from the Chinese Academy of Gneiss Dome, Eastern Desert, Egypt. International Journal of Earth Sciences. This study was financially supported by the Strategic Priority Sciences 98, 481–97. Research Programme (B) of the Chinese Academy of Sciences Andersen T (2002) Correction of common lead in U–Pb analyses that do not (XDB18030300) to XHL. report 204Pb. Chemical Geology 192,59–79. Assereto R (1963) The Paleozoic formations in central Elburz (Iran) (prelimi- nary note). Rivista Italiana di Paleontologia e Stratigrafia 69, 503–43. – – References Augland LE, Andresen A and Boghdady GY (2012) U Pb ID TIMS dating of igneous and metaigneous rocks from the El-Sibai area: time constraints on Abbo A, Avigad D, Gerdes A and Güngör T (2015) Cadomian basement and tectonic evolution of the Central Eastern Desert, Egypt. International Journal Paleozoic to Triassic siliciclastics of the Taurides (Karacahisar dome, south- of Earth Sciences 101,25–37. central Turkey): paleogeographic constraints from U–Pb–Hf in zircons. Avigad D, Kolodner K, McWilliams M, Persing H and Weissbrod T (2003) Lithos 227, 122–39. Origin of northern Gondwana Cambrian sandstone revealed by detrital zir- Abbo A, Avigad D, Gerdes A, Morag N and Vainer S (2020) Cadomian (ca. con SHRIMP dating. Geology 31, 227–30. 550 Ma) magmatic and thermal imprint on the North Arabian-Nubian Avigad D, Morag N, Abbo A and Gerdes A (2017) Detrital rutile U–Pb per- Shield (south and central Israel): new age and isotopic constraints. spective on the origin of the great Cambro–Ordovician sandstone of North Precambrian Research 346, 105804. doi: 10.1016/j.precamres.2020.105804. Gondwana and its linkage to orogeny. Gondwana Research 51,17–29. Abd El-Rahman Y, Abu Anbar M, Li XH, Li J, Ling XX, Wu LG and Masoud Avigad D, Weissbrod T, Gerdes A, Zlatkin, O, Ireland TR and Morag N AE (2019) The evolution of the Arabian-Nubian Shield and survival of its (2015) The detrital zircon U–Pb–Hf fingerprint of the northern Arabian– zircon U–Pb–Hf–O isotopic signature: a tale from the Um Had Nubian Shield as reflected by a Late Ediacaran arkosic wedge (Zenifim Conglomerate, central Eastern Desert, Egypt. Precambrian Research 320, Formation; subsurface Israel). Precambrian Research 266,1–11. 46–62. Bagheri S and Stampfli GM (2008) The Anarak, Jandaq and Posht-e-Badam Agard P, Omrani J, Jolivet L, Whitchurch H, Vrielynck B, Spakman W, metamorphic complexes in central Iran: new geological data, relationships Monie P, Meyer B and Wortel R (2011) Zagros orogeny: a subduction- and tectonic implications. Tectonophysics 451, 123–55. dominated process. Geological Magazine 148, 692–725. Be’eri-Shlevin Y, Eyal M, Eyal Y, Whitehouse MJ and Litvinovsky B (2012) Alavi M (1994) Tectonics of the Zagros orogenic belt of Iran: new data and The Sa’al volcano-sedimentary complex (Sinai, Egypt), a latest interpretations. Tectonophysics 229, 211–38. Mesoproterozoic volcanic arc in the northern Arabian Nubian Shield. Alavi M and Bolourchi MH (1973) Explanatory Text of the Maku Quadrangle Geology 40, 403–6. Map 1:250 000. Geological Quadrangle, A1. Tehran: Geological Survey of Be’eri-Shlevin Y, Katzir Y and Whitehouse MJ (2009) Post-collisional tec- Iran, 44 pp. tono-magmatic evolution in the northern Arabian Nubian Shield (ANS): Alavi-Naini M (2009) Stratigraphy of Iran. Tehran: Geological Survey of Iran, time constraints from ionprobe U–Pb dating of zircon. Journal of the 507 pp. (in Persian) Geological Society, London 166,1–15. Ali BH, Wilde SA and Gabr MMA (2009) Granitoid evolution in Sinai, Egypt, Bea F, Mazhari A, Montero P, Amini S and Ghalamghash J (2011) Zircon based on precise SHRIMP U–Pb zircon geochronology. Gondwana Research dating, Sr and Nd isotopes, and element geochemistry of the Khalifan pluton, 15,38–48. NW Iran: evidence for Variscan magmatism in a supposedly Cimmerian Ali KA, Jeon H, Andresen A, Li SQ, Harbi HM and Hegner E (2014) U–Pb superterrane. Journal of Asian Earth Science 44, 172–9. zircon geochronology and Nd–Hf–O isotopic systematics of the Bea R, Abu-Anbar N, Montero P, Peres P and Talavera C (2009) The ~844 Ma Neoproterozoic Hadb adh Dayheen ring complex, Central Arabian Shield, Moneiga quartz-diorites of the Sinai, Egypt: evidence for Andean-type arc or Saudi Arabia. Lithos 206–207, 348–60. rift-related magmatism in the Arabian-Nubian Shield? Precambrian Ali KA, Kröner A, Hener E, Wong J, Li SQ, Gahlan HA and Abu El Ela FF Research 175, 161–8. (2015) U–Pb zircon geochronology and Hf–Nd isotopic systematics of Wadi Belousova EA, Griffin WL, O’Reilly SY and Fisher NI (2002) Igneous zircon: Beitan granitoid gneisses, South Eastern Desert, Egypt. Gondwana Research trace element composition as an indicator of host rock type. Contributions to 27, 811–24. Mineralogy and Petrology 143, 602–22. Ali KA, Stern RJ, Manton WI, Johnson PR and Mukherjee SK (2010) Berberian M and King GCP (1981) Towards a paleogeography and tectonic Neoproterozoic diamictite in the Eastern Desert of Egypt and Northern evolution of Iran. Canadian Journal of Earth Sciences 18, 210–65. Saudi Arabia: evidence of ~750 Ma glaciation in the Arabian-Nubian Bergeron J (1894) Notes paléontologiques I. Crustacés. Bulletin de la Société Shield. International Journal of Earth Sciences 90, 705–26. géologique de France 21 (for 1893), 333–46. Ali KA, Stern RJ, Manton WI, Kimura JI and Khamees H (2009) Black LP, Kamo SL, Allen CM, Aleinikoff JN, Davis DW, Korsch RJ and Geochemistry, Nd isotopes and U–Pb SHRIMP zircon dating of Foudoulis C (2003) TEMORA 1: a new zircon standard for Phanerozoic Neoproterozoic volcanic rocks from the Central Eastern Desert of Egypt: U–Pb geochronology. Chemical Geology 200, 155–70. new insights into the ~750 Ma crust-forming event. Precambrian Research Buchs DM, Bagheri S, Martin L, Hermann J and Arculus R (2013) Paleozoic 171,1–22. to Triassic ocean opening and closure preserved in Central Iran: constraints Alirezaei S and Hassanzadeh J (2012) Geochemistry and zircon geochronology from the geochemistry of meta-igneous rocks of the Anarak area. Lithos 172– of the Permian A-type Hasanrobat granite, Sanandaj–Sirjan belt: a new rec- 173, 267–87. ord of the Gondwana break-up in Iran. Lithos 151, 122–34. Cawood PA, Wang Y, Xu Y and Zhao G (2013) Locating South China in Álvaro JJ, Ahlberg P, Babcock LE, Bordonaro OL, Choi DK, Cooper RA, Rodinia and Gondwana: a fragment of greater India lithosphere? Geology Ergaliev GKH, Gapp IW, Ghobadi Pour M, Hughes NC, Jago JB, 41, 903–6. Korovnikov I, Laurie JR, Lieberman BS, Paterson JR, Pegel TV, Popov Charvet J (2013) The Neoproterozoic–Early Paleozoic tectonic evolution of the LE, Rushton AWA, Sukhov S, Tortello MF, Zhou Z and Żylińska A South China Block: an overview. Journal of Asian Earth Sciences 74, 198–209. (2013) Global Cambrian trilobite palaeobiogeography assessed using parsi- Cohen KM, Finney SC, Gibbard PL and Fan J-X (2013) The ICS International mony analysis of endemicity. In Early Palaeozoic Biogeography and Chronostratigraphic Chart. Episodes 36, 199–204. Palaeogeography (eds DAT Harper and T Servais), pp. 273–96. Geological Collins AS and Pisarevsky SA (2005) Amalgamating eastern Gondwana: the Society of London, Memoirs no. 38. evolution of the Circum-Indian Orogens. Earth-Science Reviews 71, 229–70.

Compston W, Zhang Z, Cooper JA, Ma GG and Jenkins RJF (2008) Further occurrence of a 300 Ma (Paleo-Tethys) oceanic crust. American Geophysical SHRIMP geochronology on the early Cambrian of south China. American Union, Fall Meeting, Abstract I/12C-0993. Journal of Sciences 308, 399–420. Ghobadi Pour M (2006) Early Ordovician (Tremadocian) trilobites from Condon D, Zhu MY, Bowring S, Wang W, Yang AH and Jin YG (2005) U–Pb Simeh-Kuh, Eastern Alborz, Iran. In Studies in Palaeozoic Palaeontology ages from the Neoproterozoic Doushantuo Formation, China. Science 308, (eds MG Bassett and VK Deisler), pp. 93–118. Cardiff: National Museum 95–8. of Wales, Geological Series no. 25. Corfu F (2004) U–Pb age, setting and tectonic significance of the anorthosite- Ghobadi Pour M, Ghavidel-Syooki M, Álvaro JJ, Popov LE and Ehsani MH mangerite-harnockite-granite suite, Lofoten-Vesteralen, Norway. Journal of (2015a) First reported Late Ordovician trilobites from the High Zagros Petrology 45, 1799–819. Range, Iran: a biogeographic link between Gondwanan Chinese and Corfu F, Hanchar JM, Hoskin PWO and Kinny P (2003) Atlas of zircon tex- Mediterranean faunas. Geobios 48, 351–69. tures. Reviews in Mineralogy and Geochemistry 53, 469–500. Ghobadi Pour M, Popov LE, Holmer LE, Hosseini-Nezhad M, Rasuli R, Cox GM, Foden J and Collins A (2019) Late Neoproterozoic adakitic magma- Fallah K, Amini A and Jahangiri H (2015b) Early Ordovician tism of the eastern Arabian Nubian Shield. Geoscience Frontiers 10, 1981–92. (Tremadocian) faunas and biostratigraphy of the Gerd-Kuh section, eastern Davoudian AR, Genser J, Neubauer F and Shabanian N (2016) 40Ar–39Ar Alborz, Iran. Stratigraphy 12,55–61. mineral ages of eclogite from North Shahrekord in the Sanandaj–Sirjan Ghobadi Pour M, Popov LE, Kebria-ee Zadeh MR and Baars C (2011) Middle Zone, Iran: implications for the tectonic evolution of Zagros orogen. Ordovician (Darriwilian) brachiopods associated with the Neseuretus biofa- Gondwana Research 37, 216–40. cies, eastern Alborz Mountains, Iran. Memoirs of the Association of Derakhshi M and Ghasemi H (2015) Soltan Maidan Complex (SMC) in the Australian Palaeontologists 42, 263–83. eastern Alborz structural zone, northern Iran: magmatic evidence for Ghobadi Pour M, Vidal M and Hosseini-Nezhad M (2007) An Early Paleotethys development. Arabian Journal of Geosciences 8, 849–66. Ordovician trilobite assemblage from the Lashkarak Formation, Damghan Dickinson WR and Gehrels GE (2009) Use of U–Pb ages of detrital zircons to area, northern Iran. Geobios 40, 489–500. infer maximum depositional ages of strata: a test against a Colorado Plateau González-G´omez C (2005) Linguliformean brachiopods of the Middle–Upper Mesozoic database. Earth and Planetary Science Letters 288, 115–25. Cambrian transition from the Val d’Homs Formation, southern Montagne Domeier M (2018) Early Paleozoic tectonics of Asia: towards a full-plate model. Noire, France. Journal of Paleontology 79,29–47. Geoscience Frontiers 9, 789–862. Gorjansky VY (1969) Inarticulate brachiopods of the Cambrian and Dong XP, Repetski JE and Bergström SM (2004) Conodont biostratigraphy of Ordovician of the Northwest Russian Platform. Ministerstvo Geologii – the Middle Cambrian through lowermost Ordovician in Hunan, South RSFSR, Severo-Zapadnoe Territorialnoe Geologicheskoe Upravlenie 6,1 China. Acta Geologica Sinica 78, 1185–206. 173 (in Russian). Dong YP, Liu XM, Santosh M, Chen Q, Zhang XN, Li W, He DF and Zhang Grimes CB, Jhon BE, Kelemen PB, Mazdab FK, Wooden JL, Cheadle MJ, GW (2012) Neoproterozoic accretionary tectonics along the northwestern Hanghøj K and Schwartz JJ (2007) Trace element chemistry of zircons from margin of the Yangtze Block, China: constraints from zircon U–Pb geochro- oceanic crust: a method for distinguishing detrital zircon provenance. – nology and geochemistry. Precambrian Research 196–197, 247–74. Geology 35, 643 6. “ ” Du LL, Guo JH, Nutman AP, Wyman D, Geng YS, Yang CH, Liu FL, Ren LD Grimes CB, Wooden JL, Cheadle MJ and John BE (2015) Fingerprinting and Zhou XW (2014) Implications for Rodinia reconstructions for the ini- tectono-magmatic provenance using trace elements in igneous zircon. tiation of Neoproterozoic subduction at similar to 860 Ma on the western Contributions to Mineralogy and Petrology 170, 46. doi: 10.1007/s00410- margin of the Yangtze Block: evidence from the Guandaoshan Pluton. 015-1199-3. Lithos 196,67–82. Hamdi B, Brasier MD and Zhiwen J (1989) Earliest skeletal fossils from – Duan L, Meng QR, Zhang CL and Liu XM (2011) Tracing the position of the Precambrian Cambrian boundary strata, Elburz Mountains, Iran. – South China block in Gondwana: U–Pb ages and Hf isotopes of Devonian Geological Magazine 126, 283 9. detrital zircons. Gondwana Research 19, 141–9. Hamdi B, Rozanov AY and Zhuravlev AY (1995) Latest Middle Cambrian – Etemad-Saeed N, Hosseini-Barzi M, Adabi M, Miller NR, Sadeghi A, metazoan reef from northern Iran. Geological Magazine 132, 367 73. Houshmandzadeh A and Stockli DF (2015) Evidence for ca. 560 Ma Hassan M, Stüwe K, Abu-Alam TS, Klötzli U and Tiepolo M (2016) Time Ediacaran glaciation in the Kahar Formation, central Alborz Mountains, constraints on deformation of the Ajjaj branch of one of the largest northern Iran. Gondwana Research 31, 164–83. Proterozoic shear zones on Earth: the Najd Fault System. Gondwana – Falcon NL (1974) Southern Iran: Zagros Mountains. In Mesozoic–Cenozoic Research 34, 346 62. Hassanzadeh J, Stockli DF, Horton BK, Axen GJ, Stockli LD, Grove M, Orogenic Belts: Data for Orogenic Studies (ed. AM Spencer), pp. 199–211. Schmitt AK and Walker JD (2008) U–Pb zircon geochronology of late Geological Society of London, Special Publication no. 4. Neoproterozoic–Early Cambrian granitoids in Iran: implications for paleo- Fazlnia A, Moradian A, Rezaei K, Moazzen M and Alipour S (2007) geography, magmatism, and exhumation history of Iranian basement. Synchronous activity of anorthositic and S-type granitic magmas in Tectonophysics 451,71–96. Chah–Dozdan batholite, Neyriz, Iran: evidence of zircon SHRIMP and Hassanzadeh J and Wernicke BP (2016) The Neotethyan Sanandaj–Sirjan monazite CHIME dating. Journal of Sciences, Islamic Republic of Iran 18, zone of Iran as an archetype for passive margin-arc transitions. Tectonics 221–37. 35, 586–621. Fergusson CL, Nutman AP, Mohajjel M and Bennett V (2016) The Sanandaj– Havlíček V (1982) Lingulacea, Paterinacea, and Siphonotretacea (Brachiopoda) Sirjan zone in the Neo-Tethyan suture, western Iran: zircon U–Pb evidence in the Lower Ordovician sequence of Bohemia. Sborník geologických věd. of late Palaeozoic rifting of northern Gondwana and mid-Jurassic orogenesis. Paleontologie 25,9–82. Gondwana Research 40,43–57. Hedge CE (1984) Precambrian Geochronology of Part of Northwestern Saudi Gehrels GE (2014) Detrital zircon U–Pb geochronology applied to tectonics. Arabia, Kingdom of Saudi Arabia. Kingdom of Saudi Arabian Deputy Annual Review of Earth and Planetary Sciences 42, 127–49. Ministry for Mineral Resources. United States Geological Survey Open- Ghanem H, McAleer RJ, Jarrar G, Hseinat M and Whitehouse M (2020) 40Ar/ File Report 84-381, 14 pp. 39Ar and U–Pb SIMS zircon ages of Ediacaran dikes from the Arabian- Holmer LE (1989) Middle Ordovician phosphatic inarticulate brachiopods Nubian Shield of south Jordan. Precambrian Research 343, 105714. doi: from Västergötland and Dalarna, Sweden. Fossils and Strata 26,1–172. 10.1016/j.precamres.2020.105714. Honarmand M, Li XH, Nabatian G and Neubauer F (2017) In-situ zircon U– Ghasemi H and Dayhimi M (2015) Devonian alkaline basic magmatism in Pb age and Hf–O isotopic constraints on the origin of the Hasan-Robat A- Eastern Alborz, north of Shahrood: evidence for Paleotethys rifting. type granite from Sanandaj–Sirjan zone, Iran: implications for reworking of Iranian Journal of Geology 32,19–32 (in Persian). Cadomian arc igneous rocks. Mineralogy and Petrology 111, 659–75. Ghazi M, Hassanipak AA, Tucker PJ, Mobasher K and Duncan RA (2001) Honarmand M, Li XH, Nabatian G, Rezaeian M and Etemad-Saeed N (2016) Geochemistry and 40Ar–39Ar ages of the Mashhad Ophiolite, NE Iran: a rare Neoproterozoic–Early Cambrian tectono-magmatic evolution of the Central

Iranian terrane, northern margin of Gondwana: constraints from detrital zir- northwestern part of the Arabian Shield. International Geology Review 60, con U–Pb and Hf–O isotope studies. Gondwana Research 37, 285–300. 1290–319. Horton BK, Hassanzadeh J, Stockli DF, Axen GJ, Gillis RJ, Guest B, Amini Kruse PD and Zhuravlev AY (2008) Middle-Late Cambrian Rankenella- AH, Fakhari M, Zamanzadeh SM and Grove M (2008) Detrital zircon prov- Girvanella reefs of the Mila Formation, northern Iran. Canadian Journal enance of Neoproterozoic to Cenozoic deposits in Iran: implications for of Earth Sciences 45, 619–39. chronostratigraphy and collisional tectonics. Tectonophysics 451,97–122. Lammerer B, Langheinrich G and Manutchehr-Daini M (1984) Geological Hoskin PWO and Ireland TR (2000) Rare earth element chemistry of zircon investigations in the Binalud Mountains (NE Iran). Neues Jahrbuch für and its use as a provenance indicator. Geology 28, 627–30. Geologie und Paläontologie, Abhandlungen 168, 269–77. Hoskin PWO and Schaltegger U (2003) The composition of zircon and igne- Lan ZW, Li XH, Chu X, Tang G, Yang S, Yang H, Liu H, Jiang T and Wang T ous and metamorphic petrogenesis. Reviews in Mineralogy and Geochemistry (2017) SIMS U–Pb zircon ages and Ni-Mo-PGE geochemistry of the lower 53,25–104. Cambrian Niutitang Formation in South China: constraints on Ni-Mo-PGE Houshmandzadeh A, Soheile M and Hamdi B (1990) Explanatory Text of the mineralization and stratigraphic correlations. Journal of Asian Earth Sciences Eqlid Quadrangle Map 1:25000. Geological Quadrangle, No. G 10. Tehran: 137, 141–62. Geological Survey of Iran, Ministry of Mines and Metals. Lan ZW, Li XH, Zhu MY, Zhang QR and Li QL (2015) Revisiting the Liantuo James NP and Kobluk DR (1978) Lower Cambrian patch reefs and associated Formation in Yangtze Block, South China: SIMS U–Pb zircon age constraints sediments, Southern Canada. Sedimentology 25,1–35. and regional and global significance. Precambrian Research 263, 123–41. James NP, Kobluk DR and Klapa CF (1988) Early Cambrian patch reefs, Lasemi Y and Amin-Rasouli H (2007) Archaeocyathan buildups within an Southern Labrador. In Reefs. Canada and Adjacent Area (eds HHJ entirely siliciclastic succession: new discovery in the Toyonian Lalun Geldsetzer, NP James and GE Tebbutt), pp. 141–50. Canadian Society of Formation of northern Iran, the Proto-Paleotethys passive margin of Petroleum Geologist Memoir 13. northern Gondwana. Sedimentary Geology 201, 302–20. Jamshidi Badr M, Collins AS, Masoudi F, Cox G and Mohajjel M (2013) The Li L, Lin S, Xing G, Jiang Y and He J (2017) First direct evidence of Pan- – U Pb age, geochemistry and tectonic significance of granitoids in the Soursat African orogeny associated with Gondwana assembly in the Cathaysia – Complex, Northwest Iran. Turkish Journal of Earth Sciences 22,1 31. doi: 10. Block of Southern China. Scientific Reports 7, 794. doi: 10.1038/s41598- 3906/yer-1001-37. 017-00950-x. Johnson PR, Andersen A, Collins AS, Fowler AR, Fritz H, Ghebreab W, Li XH, Abd El-Rahman Y, Abu Anbar M, Li J, Ling XX, Wu LG and Masoud – Kusky T and Stern RJ (2011) Late Cryogenian Ediacaran history of the AE (2018) Old continental crust underlying juvenile oceanic arc: evidence Arabian-Nubian Shield: a review of depositional, plutonic, structural, and from northern Arabian-Nubian Shield, Egypt. Geophysical Research tectonic events in the closing stages of the northern East African Orogen. Letters 45, 3001–8. – Journal of African Earth Sciences 10,1 179. Li XH, Li WX, Li ZX, Lo CH, Wang J, Ye MF and Yang YH (2009) Johnson PR, Halverson GP, Kusky TM, Stern RJ and Pease V (2013) Amalgamation between the Yangtze and Cathaysia Blocks in South Volcanosedimentary basins in the Arabian-Nubian Shield: markers of China: constraints from SHRIMP U–Pb zircon ages, geochemistry and repeated exhumation and denudation in a Neoproterozoic accretionary oro- Nd–Hf isotopes of the Shuangxiwu volcanic rocks. Precambrian Research – gen. Geosciences 3, 389 445. 174, 117–28. Kargaranbafghi F, Neubauer F and Genser J (2015) The tectonic evolution of Li XH, Li ZX and Li WX (2014) Detrital zircon U–Pb age and Hf isotope – western Central Iran seen through detrital white mica. Tectonophysics 651 constrains on the generation and reworking of Precambrian continental – 652, 138 51. crust in the Cathaysia Block, South China: a synthesis. Gondwana Kebria-ee Zadeh MR, Ghobadi Pour M, Popov LE, Baars CH and Jahangiri H Research 25, 1202–15. (2015) First record of the Ordovician fauna in Mila-Kuh, eastern Alborz, Li XH, Tang GQ, Gong B, Yang YH, Hou KJ, Hu ZC, Li QL, Liu Y and Li WX – northern Iran. Estonian Journal of Earth Sciences 64, 121 39. (2013) Qinghu zircon: a working reference for microbeam analysis of U–Pb Kennedy A, Kozdrój W, Johnson PR and Kattan FH (2011a) SHRIMP age and Hf and O isotopes. Chinese Science Bulletin 58, 4647–54. Geochronology in the Northern Arabian Shield. Part III. Data Acquisition Li ZX, Bogdanova SV, Collins AS, Davidson A, De Waele B, Ernst RE, 2006. Saudi Geological Survey Open-File Report SGS-OF-2007-9, 85 pp. Fitzsimons ICW, Fuck RA, Gladkochub DP, Jacobs J, Karlstrom KE, Kennedy A, Kozdrój W, Kadi K, Kozdrój MZ and Johnson PR (2011b) Lu S, Natapov LM, Pease V, Pisarevsky SA, Thrane K and Vernikovsky SHRIMP Geochronology in the Arabian Shield (Midyan Terrane, Afif V (2008) Assembly, configuration and break-up history of Rodinia: a synthe- Terrane) and Nubian Shield (Central Eastern Desert Terrane), Part V: sis. Precambrian Research 160, 179–210. Data Acquisition 2009. Saudi Geological Survey. Open-File Report SGS- Liu XM., Gao S, Diwu SR and Ling W (2008) Precambrian crustal growth of OF-2010-11, 80 pp. Yangtze craton as revealed by detrital zircon studies. American Journal of Kennedy A, Kozdrój W, Kattan FH, Kozdrój MZ and Johnson PR (2010) Science 308, 421–68. SHRIMP Geochronology in the Arabian Shield (Midyan Terrane, Afif Ludwig KR (2003) User’s Manual for Isoplot 3.00: A Geochronological Terrane, Ad Dawadimi Terrane) and Nubian Shield (Central Eastern Toolkit for Microsoft Excel. Berkeley Geochronology Center, Special Desert), Part IV: Data Acquisition 2008. Saudi Geological Survey Open- Publication no. 4. File Report SGS-OF-2010-10, 101 pp. McDonough WF and Sun S (1995) The composition of the Earth. Chemical Khudeir AA, Paquette JL, Nicholson K, Johansson Å, Rooney TO, Hamdi S, Geology 120, 223–53. El-Fadly MA, Corcoran L, Malone SJ and El-Rus MAA (2021) On the cra- McKerrow WS, Scotese CR and Brasier MD (1992) Early Cambrian tonization of the Arabian-Nubian Shield: constraints from gneissic gran- continental reconstructions. Journal of the Geological Society, London 149, itoids in south Eastern Desert, Egypt. Geoscience Frontiers 12, 101148. 599–606. doi: 10.1016/j.gsf.2021.101148. Meinhold G, Bassis A, Hinderer M, Lewin A and Berndt J (2021) Detrital Kirschvink JL (1992) A paleogeographic model for Vendian and Cambrian zircon provenance of north Gondwana Palaeozoic sandstones from Saudi time. In The Proterozoic Biosphere: A Multidisciplinary Study (eds JW Arabia. Geological Magazine 158, 442–58. Schopf, C Klein and DD Maris), pp. 567–81. Cambridge: Cambridge Meinhold G, Hashemi Azizi SH and Berndt J (2020) Permian–Triassic mag- University Press. matism in response to Palaeotethys subduction and pre-Late Triassic arrival Kolodner K, Avigad D, McWilliams M, Wooden JL, Weissbrod T and of northeast Gondwana-derived continental fragments at the southern Feinstein S (2006) Provenance of north Gondwana Cambrian– Eurasian margin: detrital zircon evidence from Triassic sandstones of Ordovician sandstone: U–Pb SHRIMP dating of detrital zircons from Central Iran. Gondwana Research 83, 118–31. Israel and Jordan. Geological Magazine 143, 367–91. Meinhold G, Morton AC and Avigad D Kozdrój W, Kennedy AK, Johnson PR, Ziółkowska-Kozdrój M and Kadi K (2013) New insights into peri- (2018) Geochronology in the southern Midyan terrane: a review of con- Gondwana paleogeography and the Gondwana super-fan system from detri- – – straints on the timing of magmatic pulses and tectonic evolution in a tal zircon U Pb ages. Gondwana Research 23, 661 5.

Merdith AS, Williams SE, Collins AS, Tetley MG, Mulder JA, Blades ML, Heidelberger Geowissenschaftliche Abhandlungen 33. Heidelberg: Young A, Armistead SE, Cannon J, Zahirovic S and Müller RD (2021) Ruprecht-Karls-Universität, 174 pp. Extending full-plate tectonic models into deep time: linking the Pallister JS, Stacey JS, Fischer LB and Premo WR (1988) Precambrian ophio- Neoproterozoic and the Phanerozoic. Earth-Science Reviews 214, 103477. lites of Arabia – geologic settings, U–Pb geochronology, Pb-isotope charac- doi: 10.1016/j.earscirev.2020.103477. teristics, and implications for continental accretion. Precambrian Research Mergl M (2002) Linguliformean and craniiformean brachiopods of the 38,1–54. Ordovician (Třenice to Dobrotiva formations) of the Barrandian, Popov LE, Bassett MG, Holmer LE and Ghobadi Pour M (2009a) Early ontog- Bohemia. Acta Museis Nationale Prague, Series B, Natural History 58,1–82. eny and soft tissue preservation in siphonotretide brachiopods: new data Moghadam HS, Griffin W, Li XH, Santos JF, Karsli O, Stern RJ, Ghorbani G, from the Cambrian–Ordovician of Iran. Gondwana Research 16, 151–61. Gain S, Murphy R and O’Reilly SY (2018) Crustal evolution of NW Iran: Popov LE and Cocks LRM (2017) The World’s second oldest strophomenoid- Cadomian arcs, Archean fragments and the Cenozoic magmatic flare-up. dominated benthic assemblage in the first Dapingian (Middle Ordovician) Journal of Petrology 58, 2143–90. brachiopod fauna identified from Iran. Journal of Asian Earth Sciences Moghadam HS, Li QL, Griffin WL, Karsli O, Santos JF, Ottley CJ, Ghorbani 140,1–12. G, and O’Reilly SY (2020a) Tracking the birth and growth of Cimmeria: geo- Popov LE, Ghobadi Pour M, Bassett MG and Kebria-ee M (2009b) chronology and origins of intrusive rocks from NW Iran. Gondwana Billingsellide and orthide brachiopods: new insights into earliest Research 87, 188–206. Ordovician evolution and biogeography from northern Iran. Moghadam HS, Li QL, Griffin WL, Stern RJ, Ishizuka O, Henry H, Lucci F, Palaeontology 52,35–52. O’Reilly SY and Ghorbani G (2020b) Repeated magmatic buildup and deep Popov LE, Ghobadi Pour M and Hosseini M (2008) Early to Middle “hot zones” in continental evolution: the Cadomian crust of Iran. Earth and Ordovician lingulate brachiopods from the Lashkarak Formation, Eastern Planetary Science Letters 531, 115989. doi: 10.1016/j.epsl.2019.115989. Alborz Mountains, Iran. Alcheringa 32,1–35. Moghadam HS, Li XH, Griffin WL, Stern RJ, Thomsen TB, Meinhold G, Popov LE, Hairapetian V, Ghobadi Pour M, Buttler C, Evans DH, Hejazi SH Aharipour R and O’Reilly SY (2017) Early Paleozoic tectonic reconstruction and Jahangir H (2014) Llandovery fauna of Iran during the post-extinction of Iran: tales from detrital zircon geochronology. Lithos 268–271,87–101. recovery. In Abstract Volume and Proceedings of The Third International Moghadam HS, Li XH, Ling XX, Stern RJ, Santos JF, Meinhold G, Ghorbani Symposium of the International Geosciences Programme Project 589 G and Shahabi S (2015) Petrogenesis and tectonic implications of Late (IGCP-589). Development of the Asian Tethyan Realm: Genesis Process Carboniferous A-type granites and gabbronorites in NW Iran: geochrono- and Outcomes, Tehran, Iran, 19–26 October 2014, pp. 105–10. logical and geochemical constraints. Lithos 212–215, 266–79. Popov LE, Holmer LE, Bassett MG, Ghobadi Pour M and Percival IG (2013) Mohajjel M, Fergusson C and Sahandi MR (2003) Cretaceous–Tertiary con- Biogeography of Ordovician linguliform and craniiform brachiopods. In vergence and continental collision, Sanandaj–Sirjan Zone, western Iran. Early Paleozoic Biogeography and Palaeogeography (eds DAT Harper and Journal of Asian Earth Sciences 21, 397–412. T Servais), pp. 117–26. Geological Society of London, Memoirs no. 38. Moosavi E, Mohajjel M and Rashidnejad-Omran N (2014) Systematic change Popov LE, Holmer LE and Miller JF (2002) Lingulate brachiopods from the in orientation of linear mylonitic fabrics: an example of strain partitioning Cambrian– Ordovician boundary beds of Utah. Journal of Paleontology during transpressional deformation in north Golpaygan, Sanandaj–Sirjan 76, 211–28. zone, Iran. Journal of Asian Earth Sciences 94,55–67. Portner RA, Daczko NR, Murphy MJ and Pearson NJ (2011) Enriching Morag N, Avigad D, Gerdes A, Belousova E and Harlavan Y (2011) Crustal mantle melts within a dying mid-ocean spreading ridge: insights from Hf- evolution and recycling in the northern Arabian-Nubian Shield: new per- isotope and trace element patterns in detrital oceanic zircon. Lithos 126, spectives from zircon Lu–Hf and U–Pb systematics. Precambrian Research 355–68. 186, 101–16. Rachidnejad-Omran N, Emami MH, Sabzehei M, Rastad E, Bellon H and Morag N, Avigad D, Gerdes A and Harlavand Y (2012) 1000–580 Ma crustal Pique A (2002) Lithostratigraphie et historie paléozoïque à paléocène des evolution in the northern Arabian-Nubian Shield revealed by U–Pb–Hf of complexes métamorphiques de la region de Muteh, zone de Sanandaj– detrital zircons from late Neoproterozoic sediments (Elat area, Israel). Sirjan (Iran méridional). Comptes Rendus Geoscience 334, 1185–91. Precambrian Research 208–211, 197–212. Rahmati-Ilkhchi M, Faryad SW, Holub FV, Košler J and Frank W (2011) Moritz R, Ghazban F and Singer BS (2006) Eocene gold ore formation at Magmatic and metamorphic evolution of the Shotur Kuh metamorphic com- Muteh, Sanandaj–Sirjan tectonic zone, eastern Iran: a result of late-stage plex (Central Iran). International Journal of Earth Sciences 100,45–62. extension and exhumation of metamorphic basement rocks within the Ramezani J and Tucker RD (2003) The Saghand Region, Central Iran: U–Pb Zagros orogen. Economic Geology 101, 1497–524. geochronology, petrogenesis and implications for Gondwana Tectonics. Mouthereau F, Lacombe O and Vergés J (2012) Building the Zagros collisional American Journal of Science 303, 622–65. orogen: timing, strain distribution and the dynamics of Arabia/Eurasia plate Ranjan S, Upadhyay D, Pruseth KL and Nanda JK (2020) Detrital zircon evi- convergence. Tectonophysics 532–535,27–60. dence for change in geodynamic regime continental crust formation 3.7–3.6 Müller KJ (1973) Late Cambrian and Early Ordovician conodonts from billion years ago. Earth and Planetary Science Letters 538, 116206. doi: 10. northern Iran. Geological Survey of Iran, Report 30,1–77. 1016/j.epsl.2020.116206. Murphy JB, Pisarevsky SA, Nance RD and Keppie JD (2004) Neoproterozoic– Richards JP (2015) Tectonic, magmatic, and metallogenic evolution of the Early Paleozoic evolution of peri-Gondwanan terranes: implications for Tethyan orogeny: from subduction to collision. Ore Geology Reviews 70, Laurentia–Gondwana connections. International Journal of Earth Sciences 323–45. 93, 659–82. Robinson FA, Foden JD, Collins AS and Payne JL (2014) Arabian Shield Neubauer F (2014) Gondwana-land goes Europe. Austrian Journal of Earth magmatic cycles and their relationship with Gondwana assembly: insights Sciences 107, 147–55. from zircon U–Pb and Hf isotopes. Earth and Planetary Science Letters Nutman AP, Mohajjel M, Bennett VC and Fergusson CL (2014) Gondwanan 408, 207–25. Eoarchean–Neoproterozoic ancient crustal material in Iran and Turkey: Rowland SM and Gangloff RA (1988) Structure and paleoecology of Lower zircon U–Pb–Hf isotopic evidence. Canadian Journal of Earth Sciences 51, Cambrian reefs. Palaios 3, 111–35. 272–85. Rowland SM and Shapiro RS (2002) Reef patters and environmental influences Okada Y, Sawaki Y, Komiya T, Hirata T, Takahata N, Sano Y, Han J and in the Cambrian and Earliest Ordovician. In Phanerozoic Reef Patterns (eds Maruyama S (2014) New chronological constraints for Cryogenian to W Kiessling, E Flügel and J Golonka), pp. 95–128. SEPM Special Publication Cambrian rocks in the Three Gorges, Weng’an and Chengjiang areas, no. 72. South China. Gondwana Research 25, 1027–44. Rubatto D (2002) Zircon trace element geochemistry: partitioning with garnet Paidar-Saravi H (1989) Petrographisch-lagerstättenkundliche Untersuchungen and the link between U–Pb ages and metamorphism. Journal of Chemical an goldführenden Gesteinen im Muteh-Gebiet im Westen vom Zentraliran. Geology 184, 123–38.

Rubatto D and Hermann J (2007) Experimental zircon/melt and zircon/garnet to early Cambrian records from southwestern Mongolia. Geological trace element partitioning and implications for the geochronology of crustal Society of America Bulletin 128, 442–68. rocks. Chemical Geology 241,38–61. Song SG, Niu YL, Wei CJ, Ji JQ and Su L (2010) Metamorphism, anatexis, Saccani E, Azimzadeh Z, Dilek Y and Jahangiri A (2013) Geochronology and zircon ages and tectonic evolution of the Gongshan block in the northern petrology of the Early Carboniferous Misho Mafic Complex (NW Iran), and Indochina continent-an eastern extension of the Lhasa Block. Lithos 120, implications for the melt evolution of Paleo-Tethyan rifting in Western 327–46. Cimmeria. Lithos 162, 264–78. Squire RJ, Campbell IH, Allen CM and Wilson CJL (2006) Did the Şengör AMC (1990) A new model for the late Paleozoic–Mesozoic tectonic evo- Transgondwanan Supermountain trigger the explosive radiation of animals lution of Iran and implications for Oman. In The Geology and Tectonics of the on earth? Earth and Planetary Science Letters 250, 116–33. Oman Region (eds AHF Robertson, MP Searle and AC Reis), pp. 797–831. Stampfli GM, Hochard C, Vérard C, Wilhem C and von Raumer J (2013) The Geological Society of London, Special Publication no. 49. formation of Pangea. Tectonophysics 593,1–19. Shabanian N, Davoudian AR, Azizi H, Asahara Y, Neubauer F, Genser J, Steiner M, Li G, Qian Y, Zhu M and Erdtmann BD (2007) Neoproterozoic to Dong Y and Lee JKW (2020) Petrogenesis of the Carboniferous Ghaleh- early Cambrian small shelly fossil assemblages and a revised biostratigraphic Dezh metagranite, Sanandaj–Sirjan zone, Iran: constraints from new zircon correlation of the Yangtze Platform (China). Palaeogeography, U–Pb and 40Ar/39Ar ages and Sr–Nd isotopes. Geological Magazine 157, Palaeoclimatology, Palaeoecology 254,67–99. 1823–52. Stephan T, Kroner U and Romer RL (2019) The pre-orogenic detrital zircon Shahkarami S, Mángano MG and Buatois LA (2017a) Discriminating ecologi- record of the Peri-Gondwanan crust. Geological Magazine 156, 281–307. cal and evolutionary controls during the Ediacaran–Cambrian transition: Stern RJ (1994) Arc assembly and continental collision in the Neoproterozoic trace fossils from the Soltanieh Formation of northern Iran. East African Orogen: implications for the assembly of Gondwanaland. Palaeogeography, Palaeoclimatology, Palaeoecology 476,15–27. Annual Review of Earth and Planetary Sciences 22, 319–51. Shahkarami S, Mángano MG and Buatois LA (2017b) Ichnostratigraphy of Stevens Goddard AL, Trop JM and Ridgway KD (2018) Detrital zircon record the Ediacaran–Cambrian boundary: new insights on lower Cambrian biozo- of a Mesozoic collisional forearc basin in south central Alaska: the tectonic nations from the Soltanieh Formation of northern Iran. Journal of transition from an oceanic to continental arc. Tectonics 37, 529–57. Paleontology 91, 1178–98. Stöcklin J (1968) Structural history and tectonics of Iran: a review. American Shakerardakani F, Li XH, Ling XX, Li J, Tang GQ, Liu Y and Monfaredi B Association of Petroleum Geologists Bulletin 52, 1229–58. (2019) Evidence for Archean crust in Iran provided by ca. 2.7 Ga zircon xen- Thiele O (1966) Zum Alter der Metamorphose in Zentraliran. Mitteilungen der – ocrysts within amphibolites from the Sanandaj Sirjan zone, Zagros orogen. geologischen esellschaft (Wien) 58,87–101 Precambrian Research 332, 105390. doi: 10.1016/j.precamres.2019.105390. Torsvik TH (1998) Palaeozoic palaeogeography: a north Atlantic viewpoint. Shakerardakani F, Li XH, Neubauer F, Ling XX, Li J, Monfaredi B and Wu GFF 120, 109–18. LG (2020) Genesis of early Cretaceous leucogranites in the Central Torsvik TH and Cocks LRM (2013) Gondwana from top to base in space and – Sanandaj Sirjan zone Iran: reworking of Neoproterozoic metasedimentary time. Gondwana Research 24, 999–1030. – rocks in an active continental margin. Lithos 352 353, 105330. doi: 10. von Raumer JF, Bussy F, Schaltegger U, Schulz B and Stampfli GM (2013) 1016/j.lithos.2019.105330. Pre-Mesozoic Alpine basements–their place in the European Paleozoic Shakerardakani F, Neubauer F, Bernroider M, Finger F, Hauzenberger CA, framework. Geological Society of America Bulletin 125,89–108. Genser J, Waitzinger M and Monfaredi B (2021) Metamorphic stages in Wang GG, Ni P, Zhu AD, Wang XL, Li L, Hu JS, Lin WH and Huang B (2018) mountain belts during a Wilson cycle: A case study in the central 1.01–0.98 Ga mafic intra-plate magmatism and related Cu-Au mineraliza- – Sanandaj Sirjan zone (Zagros Mountains, Iran). Geoscience Frontiers. tion in the eastern Jiangnan orogen: evidence from Liujia and Tieshajie https://doi.org/10.1016/j.gsf.2021.101272. basalts. Precambrian Research 309,6–21. Shakerardakani F, Neubauer F, Bernroider M, von Quadt A, Peytcheva I, Liu Wang MX, Wang CY and Zhao JH (2013) Zircon U/Pb dating and Hf–O iso- X, Genser J, Monfaredi B and Masoudi F (2017) Geochemical and isotopic topes of the Zhouan ultramafic intrusion in the northern margin of the – evidence for Carboniferous rifting: mafic dykes in the central Sanandaj Yangtze Block, SW China: constraints on the nature of mantle source and – – Sirjan zone (Dorud Azna, West Iran). Geologica Carpathica 68, 229 47. timing of the supercontinent Rodinia breakup. Chinese Science Bulletin Shakerardakani F, Neubauer F, Liu X, Bernroider M, Monfaredi B and von 58, 777–87. Quadt A (2018) Tectonic significance of Triassic mafic rocks in the June Wang W, Zhou M, Chu Z, Xu J, Li C, Luo T and Guo J (2020) Constraints on – Complex, Sanandaj Sirjan zone, Iran. Swiss Journal of Geosciences 111, the Ediacaran–Cambrian boundary in deep-water realm in South China: evi- – 13 33. dence from zircon CA–ID–TIMS U–Pb ages from the topmost Liuchapo Shakerardakani F, Neubauer F, Masoudi F, Mehrabi B, Liu X, Dong Y, Formation. Science China Earth Sciences 63, 1176–87. Mohajjel M, Monfaredi B and Friedl G (2015) Panafrican basement and Wang YJ, Zhang F, Fan W, Zhang G, Chen S, Cawood PA and Zhang A Mesozoic gabbro in the Zagros orogenic belt in the Dorud–Azna region (2010) Tectonic setting of the South China Block in the early Paleozoic: (NW Iran): laser-ablation ICP–MS zircon ages and geochemistry. resolving intracontinental and ocean closure models from detrital zircon Tectonophysics 647–648, 146–71. U–Pb geochronology. Tectonics 29, TC6020. doi: 10.1029/2010TC002750. Sheikholeslami R, Bellon H, Emami H, Sabzehei M and Pique A (2003) Wang YJ, Zhu WG, Huang HQ, Zhong H, Bai ZJ, Fan HP and Yang YJ Nouvelles données structurales et datations 40K/40Ar surles roches (2019) Ca. 1.04 Ga hot Grenville granites in the western Yangtze Block, métamorphiques de la region de Neyriz (zone de Sanandaj–Sirjan, Iran southwest China. Precambrian Research 328, 217–34. méridional). Leur intérêt dans le carde du domaine néo-téthysien du Weber B, Steiner M, Evseev S and Yergaliev G (2013) First report of a Moyen-Orient. Comptes Rendus Geoscience 335, 981–91. Meishucun-type early Cambrian (Stage 2) ichnofauna from the Malyi Shergold H, Cooper RA, MacKinnon DI and Yochelson EL (1976) Late Karatau area (SE Kazakhstan): palaeoichnological, palaeoecological and Cambrian Brachiopoda, Mollusca, and Trilobita from Northern Victoria palaeogeographical implications. Palaeogeography, Palaeoclimatology, Land, Antarctica. Palaeontology 19, 247–91. Palaeoecology 392, 209–31. Shu L, Yao J, Wang B, Faure M, Charvet J and Chen Y (2021) Neoproterozoic Wendt J, Kaufmann B, Belka Z, Farsan N and Karimi Bavandpur A (2002) plate tectonic process and Phanerozoic geodynamic evolution of the South Devonian/Lower Carboniferous stratigraphy, facies patterns and palaeo- China Block. Earth-Science Reviews 216, 103596. doi: 10.1016/j.earscirev. geography of Iran. Part I. Southeastern Iran. Acta Geologica Polonica 52, 2021.103596. 129–68. Singh BP, Lokho K, Kishore N and Virmani N (2014) Early Cambrian ichno- Wendt J, Kaufmann B, Belka Z, Farsan N and Karimi Bavandpur A (2005) fossils from the Mussoorie syncline and revision of trace-fossil biozonation of Devonian/Lower Carboniferous stratigraphy, facies patterns and palaeo- the Lesser Himalaya, India. Acta Geologica Sinica 88, 380–93. geography of Iran. Part II. Northern and central Iran. Acta Geologica Smith EF, Macdonald FA, Petach TA, Bold U and Schrag DP (2015) Polonica 55,31–97. Integrated stratigraphic, geochemical, and paleontological late Ediacaran

Wiedenbeck M, Allé P, Corfu F, Griffen WL, Meier M, Oberli F, von Quadt Zhao JH, Zhou MF, Zheng JP and Griffin WL (2013) Neoproterozoic tonalite A, Roddick JC and Spiegel W (1995) Three natural zircon standards for U– and Trondhjemite in the Huangling complex, South China: crustal growth Th–Pb, Lu–Hf, trace element, and REE analyses. Geostandards and and reworking in a continental arc environment. American Journal of Geoanalytical Research 19,1–23. Science 313, 540–83. Yang C, Li XH, Li ZX, Zhu M and Lu K (2020) Provenance evolution of age- Zhu M (1997) Precambrian–Cambrian trace fossils from eastern Yunnan, calibrated strata reveals when and how South China Block collided with China: implications for Cambrian explosion. Bulletin of National Museum Gondwana. Geophysical Research Letters 47, e2020GL090282. doi: 10. of Natural Science 10, 275–312. 1029/2020GL090282. Zoleikhaei Y, Mulder JA and Cawood PA (2020) Integrated detrital rutile and Yang C, Zhu M, Condon DJ and Li XH (2017) Geochronological constraints zircon provenance reveals multiple sources for Cambrian sandstones in on stratigraphic correlation and oceanic oxygenation in Ediacaran– North Gondwana. Earth-Science Reviews 213, 103462. doi: 10.1016/j. Cambrian transition in South China. Journal of Asian Earth Sciences 140, earscirev.2020.103462. 75–81. – Yang YN, Wang XC, Li QL and Li XH (2016) Integrated in situ U Pb age and – – Appendix 1.: Laser ablation ICP-MS U Pb analytical Hf O analyses of zircon from Suixian Group in northern Yangtze: new ’ insights into the Neoproterozoic low–δ18O magmas in the South China techniques, Northwest University, Xi an Block. Precambrian Research 273, 151–64. Zircons were separated from the one sample from the Dorud area Yao WH, Li ZX, Li WX, Li XH and Yang JH (2014) From Rodonia to (LJ-140) in the laboratory of the Geography and Geology Gondwanaland: a tale of detrital zircon provenance analyses from the Department of Salzburg University, Austria. The selected zircon southern Nanhua basin, South China. American Journal of Science 314, grains were dated in situ on an excimer (193 nm wavelength) laser 278–313. Yeshanew FG, Pease V, Whitehouse MJ and Al-Khirbash S (2015) Zircon U– ablation inductively coupled plasma mass spectrometer (LA-ICP- Pb geochronology and Nd isotope systematics of the Abas terrane, Yemen: MS) at the State Key Laboratory of Continental Dynamics, implications for Neoproterozoic crust reworking events. Precambrian Northwest University. The ICP-MS used is an Agilent 7500a (with Research 267, 106–20. shield torch). The unique shield torch increases analytical sensitiv- Yu JH, O’Reilly SY, Wang L, Griffin WL, Zhang M, Wang R, Jiang S and Shu ity by a factor of >10 (for example, 4500 cps/ppm 238U at a spot size L (2008) Where was South China in the Rodinia supercontinent? Evidence of 40 μm and laser frequency of 10 Hz), which is important for LA- from U–Pb geochronology and Hf isotopes of detrital zircons. Precambrian ICP-MS. The GeoLas 200M laser ablation system (MicroLas, Research 164,1–15. Göttingen, Germany) was used for the laser ablation experiments. – Yuan HL, Gao S, Liu XM, Li HM, Günther D and Wu FY (2004) Accurate U Helium was used as the carrier gas. The used spot size and laser Pb age and trace element determinations of zircon by laser ablation-induc- frequency were set at 40 μm and 10 Hz, respectively. The data tively coupled plasma mass spectrometry. Geostandards and Geoanalytical – acquisition mode was peak jumping (20 ms per isotope each cycle). Research 28, 353 70. 29 204 206 207 208 Ž Raw count rates were measured for Si, Pb, Pb, Pb, Pb, ák J, Svojtka M, Gerdjikov I, Kounov A and Vangelov DA (2021) The Balkan 232 238 terranes: a missing link between the eastern and western segments of the Th and U. U, Th and Pb concentrations were calibrated by 29 Avalonian–Cadomian orogenic belt? International Geology Review, pub- using Si as an internal standard and NIST SRM 610 as the refer- lished online 12 January 2021. doi: 10.1080/00206814.2020.1861486. ence standard. Each analysis consisted of 30 s gas blank and 40 s Zanchetta S, Berra F, Zanchi A, Bergomi M, Caridroit M, Nicora A and signal acquisition. High-purity argon was used together with a cus- Heidarzadeh G (2013) The record of the Late Palaeozoic active margin of tom helium filtration column, which resulted in 204Pb and 202Hg the Palaeotethys in NE Iran: constraints on the Cimmerian orogeny. being less than 100 cps in the gas blank. Therefore, the contribution Gondwana Research 24, 1237–66. of 204Hg to 204Pb as revealed by detrital zircon studies was negli- Zanchetta S, Zanchi A, Villa IM, Poli S and Muttoni G (2009) The gible and no correction was made. 207Pb/206Pb, 206Pb/238U, Shanderman eclogites: a Late Carboniferous high-pressure event in the 207Pb/235U and 208Pb/232Th ratios, calculated using GLITTER 4.0 NW Talesh Mountains (NW Iran). In South Caspian to Central Iran (Macquarie University), were corrected for both instrumental Basins (eds M-F Brunet, M Wilmsen and JW Granath), pp. 57–78. mass bias and depth-dependent elemental and isotopic fractiona- Geological Society of London, Special Publication no. 312. Zanchi A, Zanchetta S, Berra F, Mattei M, Garzanti E, Molyneux S, Nawab A tion using Harvard zircon 91500 as an external standard. The ages and Sabouri J (2009a) The Eo-Cimmerian (Late? Triassic) orogeny in North were calculated using Isoplot 3 (Ludwig, 2003). Our measurement 206 238 Iran. In South Caspian to Central Iran Basins (eds M-F Brunet, M Wilmsen of TEMORA 1 as an unknown yielded a weighted Pb– U age of and JW Granath), pp. 31–55. Geological Society of London, Special 415 ± 4 Ma (MSWD = 0.112, n = 24) (Yuan et al. 2004), which is in Publication no. 312. good agreement with the recommended ID-TIMS age of Zanchi A, Zanchetta S, Garzanti E, Balini M, Berra F, Mattei M and Muttoni 416.75 ± 0.24 Ma (Black et al. 2003). Analytical details for age G (2009b) The Cimmerian evolution of the Nakhlak–Anarak area, central and trace and rare earth element determinations of zircons are Iran, and its bearing for the reconstruction of the history of the Eurasian mar- reported in Yuan et al.(2004). Common Pb corrections were made gin. In South Caspian to Central Iran Basins (eds M-F Brunet, M Wilmsen following the method of Andersen (2002). Because measured 204Pb – and JW Granath), pp. 261 86. Geological Society of London, Special usually accounts for <0.3 % of the total Pb, the correction is insig- Publication no. 312. nificant in most cases. Zhan R and Jin J (2014) Early–Middle Ordovician brachiopod dispersal patterns in South China. Integrative Zoology 9, 121–40. Zhang J (1995) Ordovician phosphatic inarticulate brachiopods from Cili, Appendix 2.: Laser ablation ICP-MS U–Pb analytical Hunan. Acta Palaeontologica Sinica 34, 152–70 (in Chinese with English techniques, China University of Geosciences, Beijing summary). Zhang SH (2004) South China’s Gondwana connection in the Paleozoic: pale- The separated detrital zircons from two garnet-micaschist samples omagnetic evidence. Progress in Natural Science 14,85–90. were embedded in epoxy resin discs and polished down to about Zhang Z, Xiao W, Majidifard MR, Zhu R, Wan B, Ao S, Chen L, Rezaeian M half-sections to expose the grain interiors, and then imaged under and Esmaeili R (2017) Detrital zircon provenance analysis in the Zagros reflected and transmitted light and by using CL. U(–Th)–Pb analy- Orogen, SW Iran: implications for the amalgamation history of the Neo- ses of the detrital zircons were carried out on an Agilent-7500a – Tethys. International Journal of Earth Sciences 106, 1223 38 quadrupole inductively coupled plasma mass spectrometry (LA-

ICP-MS) coupled with a New Wave SS UP193 laser sampler at the 207Pb and 208Pb is 20 ms, and is 15 ms for other elements. Elemental Geochemistry Lab of the Institute of Earth Sciences, Calibrations for the zircon analyses were carried out using NIST China University of Geosciences, Beijing. For the present work, 610 glass as an external standard and Si as an internal standard. the laser spot size was set to ~36 μm for one sample (GQ-21) U–Pb isotope fractionation effects were corrected using zircon and to 25 μm for sample GQ-12 with a small size of zircons; the 91500 (Wiedenbeck et al. 1995) as an external standard. The zircon laser energy density was set at 8.5 J cm−2 and repetition rate at TEMORA (417 Ma, Black et al. 2003) and Qinghu (159.5 ± 0.2 Ma; 10 Hz. The procedure of laser sampling includes 5-s pre-ablation, Li et al. 2013) were used as the secondary standards to supervise the 20-s sample-chamber flushing and 40-s sampling ablation. The deviation of age measurement/calculation. Data reduction was car- ablated material is carried into the ICP-MS by the high-purity ried out on the software GLITTER (version 4.4, Macquarie helium gas stream with a flux of 0.8 L min−1. The whole laser path University). The common lead correction was made following −1 −1 was fluxed with N2 (15 L min ) and Ar (1.15 L min ) in order to Andersen (2002), and Isoplot 3 (Ludwig, 2003) was used for age increase energy stability. The counting time for U, Th, 204Pb, 206Pb, calculations and plots of concordia diagrams.